l A routing switch running MPLS has routing functions. The term “router” in this document refers to a router in a generic sense or a Layer 3 Ethernet switch running MPLS.

l This chapter covers only introduction to and configuration of MPLS L3VPN. For information about MPLS basics, BGP, and VPN, refer to the relevant manuals or volumes.

l For an S9500 Series routing switch, only line processor units (LPUs) with a suffix of C, CA or CB and VPLS service processor cards (SPCs) support MPLS. For S9500 Series routing switches to support MPLS VPN functions, you need to equip them with MPLS capable LPUs or VPLS SPCs. You can identify the suffix of an LPU by the silkscreen in the upper right corner of the LPU’s front panel. As an example, the silkscreen of an LSB1P4G8CA0 LPU is P4G8CA, and therefore the suffix of the LPU is CA.

1.1 MPLS L3VPN Overview

This section covers these topics:

l Introduction to MPLS L3VPN

l MPLS L3VPN Concepts

l MPLS L3VPN Packet Forwarding

l MPLS L3VPN Networking Schemes

l MPLS L3VPN Routing Information Advertisement

l Carrier’s Carrier

l Multi-AS VPN

l HoVPN

l OSPF VPN Extension

l BGP AS Number Substitution

1.1.1 Introduction to MPLS L3VPN

MPLS L3VPN is a kind of PE-based L3VPN technology for service provider VPN solutions. It uses BGP to advertise VPN routes and uses MPLS to forward VPN packets on service provider backbones.

MPLS L3VPN provides flexible networking modes, excellent scalability, and convenient support for MPLS QoS and MPLS TE. Hence, it is widely used.

The MPLS L3VPN model consists of three kinds of devices:

l Customer edge device (CE): A CE resides on a customer network and has one or more interfaces directly connected with service provider networks. It can be a router, a switch, or a host. It neither can "sense" the existence of any VPN nor needs to support MPLS.

l Provider edge device (PE): A PE resides on a service provider network and connects one or more CEs to the network. On an MPLS network, all VPN processing occurs on the PEs.

l Provider (P) device: A P device is a backbone device on a service provider network. It is not directly connected with any CE. It only needs to be equipped with basic MPLS forwarding capability.

Figure 1-1 shows the MPLS L3VPN model.

Figure 1-1 Network diagram for MPLS L3VPN model

CEs and PEs mark the boundary between the service providers and the customers.

After a CE establishes adjacency with a directly connected PE, it advertises its VPN routes to the PE and learns remote VPN routes from the PE. A CE and a PE use BGP/IGP to exchange routing information. You can also configure static routes between them.

After a PE learns the VPN routing information of a CE, it uses BGP to exchange VPN routing information with other PEs. A PE maintains routing information about only VPNs that are directly connected, rather than all VPN routing information on the provider network.

A P device maintains only routes to PEs. It does not need to know anything about VPN routing information.

When VPN traffic travels over the MPLS backbone, the ingress PE functions as the ingress LSR, the egress PE functions as the egress LSR, while P devices function as the transit LSRs.

1.1.2 MPLS L3VPN Concepts

I. Site

Site is often mentioned in the VPN. Its meanings are described as follows:

l A site is a group of IP systems with IP connectivity that does not rely on any service provider network to implement.

l The classification of a site depends on the topology relationship of the devices, rather than the geographical positions, though the devices at a site are adjacent to each other geographically in most cases.

l The devices at a site can belong to multiple VPNs.

l A site is connected to a provider network through one or more CEs. A site can contain many CEs, but a CE can belong to only one site.

Sites connected to the same provider network can be classified into different sets by policies. Only the sites in the same set can access each other through the provider network. Such a set is called a VPN.

II. Address space overlapping

Each VPN independently manages the addresses that it uses. The assembly of such addresses for a VPN is called an address space.

The address spaces of VPNs may overlap. For example, if both VPN 1 and VPN 2 use the addresses on network segment 10.110.10.0/24, address space overlapping occurs.

III. VPN instance

In MPLS VPN, routes of different VPNs are identified by VPN instance.

A PE creates and maintains a separate VPN instance for each VPN at a directly connected site. Each VPN instance contains the VPN membership and routing rules of the corresponding site. If a user at a site belongs to multiple VPNs at the same time, the VPN instance of the site contains information about all the VPNs.

For independency and security of VPN data, each VPN instance on a PE maintains a relatively independent routing table and a separate label forwarding information base (LFIB). VPN instance information contains these items: the LFIB, IP routing table, interfaces bound to the VPN instance, and administration information of the VPN instance. The administration information of the VPN instance includes the route distinguisher (RD), route filtering policy, and member interface list.

IV. VPN-IPv4 address

Traditional BGP cannot process VPN routes which have overlapping address spaces. If, for example, both VPN 1 and VPN 2 use addresses on the segment 10.110.10.0/24 and each advertise a route to the segment, BGP selects only one of them, which results in loss of the other route.

PEs use MP-BGP to advertise VPN routes, and use VPN-IPv4 address family to solve the problem with traditional BGP.

A VPN-IPv4 address consists of 12 bytes. The first eight bytes represent the RD, followed by a 4-byte IPv4 address prefix, as shown in Figure 1-2.

Figure 1-2 VPN-IPv4 address structure

When a PE receives an ordinary IPv4 route from a CE, it must advertise the VPN route to the peer PE. The uniqueness of a VPN route is implemented by adding an RD to the route.

A service provider can independently assign RDs provided the assigned RDs are unique. Thus, a PE can advertise different routes to VPNs even if the VPNs are from different service providers and are using the same IPv4 address space.

You are recommended to configure a distinct RD for each VPN instance on a PE, guaranteeing that routes to the same CE use the same RD. The VPN-IPv4 address with an RD of 0 is in fact a globally unique IPv4 address.

By prefixing a distinct RD to a specific IPv4 address prefix, you get a globally unique VPN IPv4 address prefix.

An RD can be related to an autonomous system (AS) number, in which case it is the combination of the AS number and a discretionary number; or be related to an IP address, in which case it is the combination of the IP address and a discretionary number.

An RD can be in either of the following two formats distinguished by the Type field:

l When the value of the Type field is 0, the Administrator subfield occupies two bytes, the Assigned number subfield occupies four bytes, and the RD format is: 16-bit AS number:32-bit user-defined number. For example, 100:1.

l When the value of the Type field is 1, the Administrator subfield occupies four bytes, the Assigned number subfield occupies two bytes, and the RD format is: 32-bit IPv4 address:16-bit user-defined number. For example, 172.1.1.1:1.

For the global uniqueness of an RD, you are not recommended to set the Administrator subfield to any private AS number or private IP address.

V. VPN target attributes

MPLS L3VPN uses the BGP extended community attributes called VPN target attributes, or route target attributes, to control the advertisement of VPN routing information.

A VPN instance on a PE supports two types of VPN target attributes:

l Export target attribute: A local PE sets this type of VPN target attribute for VPN-IPv4 routes learnt from directly connected sites before advertising them to other PEs.

l Import target attribute: A PE checks the export target attribute of VPN-IPv4 routes advertised by other PEs. If the export target attribute matches the import target attribute of the VPN instance, the PE adds the routes to the VPN routing table.

In other words, VPN target attributes define which sites can receive VPN-IPv4 routes, and from which sites that a PE can receive routes.

Like RDs, VPN target attributes can be of two types of formats:

l 16-bit AS number:32-bit user-defined number. For example, 100:1.

l 32-bit IPv4 address:16-bit user-defined number. For example, 172.1.1.1:1.

VI. MP-BGP

Multiprotocol extensions for BGP-4 (MP-BGP) advertises VPN composition information and routes between PEs. It is backward compatible and supports both traditional IPv4 address family and other address families, such as VPN-IPv4 address family.

Using MP-BGP can guarantee that private routes of a VPN are advertised only in the VPN and implement communications between MPLS VPN members.

VII. Routing policy

In addition to the import and export extended communities for controlling VPN route advertisement, you can also configure import and export routing policies to control the injection and advertisement of VPN routes more precisely.

An import routing policy can further filter the routes that can be advertised to a VPN instance by using the VPN target attribute of import target attribute. It can reject the routes selected by the communities in the import target attribute. An export routing policy can reject the routes selected by the communities in the export target attribute.

After a VPN instance is created, you can configure import and/or export routing policies as needed.

VIII. Tunneling policy

A tunneling policy is used to select the tunnel for the packets of a specific VPN instance to use.

After a VPN instance is created, you can optionally configure a tunneling policy. By default, LSPs are used as tunnels and no load balancing occurs (in other words, the number of tunnels for load balancing is 1). In addition, a tunneling policy takes effect only within the local AS.

1.1.3 MPLS L3VPN Packet Forwarding

For basic MPLS L3VPN applications in a single AS, VPN packets are forwarded with two layers of labels:

l Layer 1 labels: Outer labels, used for label switching inside the backbone. They indicate LSPs from the local PEs to the remote PEs. Based on layer 1 labels, VPN packets can be label switched along the LSPs to the remote PEs.

l Layer 2 labels: Inner labels, used for forwarding packets from the remote PEs to the CEs. An inner label indicates to which site, or more precisely, to which CE the packet should be sent. A PE finds the interface for forwarding a packet according to the inner label.

If two sites (CEs) belong to the same VPN and are connected to the same PE, each of them only needs to know how to reach the remote CE.

The following takes Figure 1-3 as an example to illustrate the VPN packet forwarding procedure.

Figure 1-3 VPN packet forwarding

1) Site 1 sends an IP packet with the destination address of 1.1.1.2. CE 1 transmits the packet to PE 1.

2) PE 1 searches VPN instance entries based on the inbound interface and destination address of the packet. Once finding a matching entry, PE 1 labels the packet with both inner and outer labels and forwards the packet out.

3) The MPLS backbone transmits the packet to PE 2 by outer label. Note that the outer label is removed from the packet at the penultimate hop.

4) PE 2 searches VPN instance entries according to the inner label and destination address of the packet to determine the outbound interface and then forwards the packet out the interface to CE 2.

5) CE 2 transmits the packet to the destination by IP forwarding.

1.1.4 MPLS L3VPN Networking Schemes

In MPLS L3VPNs, VPN target attributes are used to control the advertisement and reception of VPN routes between sites. They work independently and can be configured with multiple values to support flexible VPN access control and implement multiple types of VPN networking schemes.

I. Basic VPN networking scheme

In the simplest case, all users in a VPN form a closed user group. They can forward traffic to each other but cannot communicate with any user outside the VPN.

For this networking scheme, the basic VPN networking scheme, you need to assign a VPN target to each VPN for identifying the export target attribute and import target attribute of the VPN. Moreover, this VPN target cannot be used by any other VPNs.

Figure 1-4 Network diagram for basic VPN networking scheme

In Figure 1-4, for example, the VPN target for VPN 1 is 100:1 on the PEs, while that for VPN 2 is 200:1. The two VPN 1 sites can communicate with each other, and the two VPN 2 sites can communicate with each other. However, the VPN 1 sites cannot communicate with the VPN 2 sites.

II. Hub and spoke networking scheme

For a VPN where a central access control device is required and all users must communicate with each other through the access control device, the hub and spoke networking scheme can be used to implement the monitoring and filtering of user communications.

This networking scheme requires two VPN targets: one for the "hub" and the other for the "spoke".

The VPN target setting rules for VPN instances of all sites on PEs are as follows:

l On spoke PEs (that is, the PEs connected with spoke sites), set the export target attribute to Spoke and the import target attribute to Hub.

l On the hub PE (that is, the PE connected to the hub site), specify two interfaces or sub-interfaces, one for receiving routes from spoke PEs, and the other for advertising routes to spoke PEs. Set the import target attribute of the VPN instance for the former to Spoke, and the export target attribute of the VPN instance for the latter to Hub.

Figure 1-5 Network diagram for hub and spoke networking scheme

In Figure 1-5, the spoke sites communicate with each other through the hub site. The arrows in the figure indicate the advertising path of routes from Site 2 to Site 1:

l The hub PE can receive all the VPN-IPv4 routes advertised by spoke PEs.

l All spoke PEs can receive the VPN-IPv4 routes advertised by the hub PE.

l The hub PE advertises the routes learnt from a spoke PE to the other spoke PEs. Thus, the spoke sites can communicate with each other through the hub site.

l The import target attribute of any spoke PE is distinct from the export VPN targets of the other spoke PEs. Therefore, any two spoke PEs can neither directly advertise VPN-IPv4 routes to each other nor directly access each other.

III. Extranet networking scheme

The extranet networking scheme can be used when some resources in a VPN are to be accessed by users that are not in the VPN.

In this kind of networking scheme, if a VPN needs to access a shared site, the export target attribute and the import target attribute of the VPN must be contained respectively in the import target attribute and the export target attribute of the VPN instance of the shared site.

Figure 1-6 Network diagram for extranet networking scheme

In Figure 1-6, VPN 1 and VPN 2 can access Site 3 of VPN 1.

l PE 3 can receive the VPN-IPv4 routes advertised by PE 1 and PE 2.

l PE 1 and PE 2 can receive the VPN-IPv4 routes advertised by PE 3.

l Based on the above, Site 1 and Site 3 of VPN 1 can communicate with each other, and Site 2 of VPN 2 and Site 3 of VPN 1 can communicate with each other.

l PE 3 advertises neither the VPN-IPv4 routes received from PE 1 to PE 2, nor the VPN-IPv4 routes received from PE 2 to PE 1 (that is, routes learned from an IBGP neighbor will not be advertised to any other IBGP neighbor). Therefore, Site 1 of VPN 1 and Site 2 of VPN 2 cannot communicate with each other.

1.1.5 MPLS L3VPN Routing Information Advertisement

In basic MPLS L3VPN networking, the advertisement of VPN routing information involves CEs and PEs. A P device maintains only the routes of the backbone and does not need to know any VPN routing information. A PE maintains only the routing information of the VPNs directly connected to it, rather than that of all VPNs. Therefore, MPLS L3VPN has excellent scalability.

The VPN routing information of a local CE is advertised in three phases:

1) Advertised from the local CE to the ingress PE.

2) Advertised from the ingress PE to the egress PE.

3) Advertised from the egress PE to the remote CE.

Then, a route is available between the local CE and the remote CE, and the VPN routing information can be advertised on the backbone.

The following describes these phases in detail.

I. Routing information exchange from the local CE to the ingress PE

After establishing an adjacency with the directly connected PE, a CE advertises its VPN routing information to the PE.

The route between the CE and the PE can be a static route, RIP route, OSPF route, IS-IS route, or BGP route. No matter which routing protocol is used, the CE always advertises standard IPv4 routes to the PE.

II. Routing information exchange from the ingress PE to the egress PE

After learning the VPN routing information from the CE, the ingress PE adds RDs and VPN targets for these standard IPv4 routes to form VPN-IPv4 routes, and maintains them for the VPN instance created for the CE.

Then, the ingress PE advertises the VPN-IPv4 routes to the egress PE through MP-BGP.

Finally, the egress PE compares the export target attribute of the VPN-IPv4 routes with the import target attribute that it maintains for the VPN instance and determines whether to add the routes to the routing table of the VPN instance.

PEs use IGP to ensure the connectivity between them.

III. Routing information exchange from the egress PE to the remote CE

A remote CE can learn VPN routes from the egress PE in a number of ways. The routes can be static routes, RIP routes, OSPF routes, IS-IS routes, or EBGP routes. The exchange of routing information between the egress PE and the remote CE is the same as that between the local CE and the ingress PE.

1.1.6 Carrier’s Carrier

I. Introduction to carrier's carrier

It is possible that a customer of the MPLS L3VPN service provider is also a service provider. In this case, the MPLS L3VPN service provider is called the provider carrier or the Level 1 carrier, while the customer is called the customer carrier or the Level 2 carrier. This networking model is referred to as carrier’s carrier. In this model, the Level 2 service provider serves as a CE of the Level 1 service provider.

For good scalability, the Level 1 carrier does not inject the external routes of a Level 2 carrier; it only injects routes for switching packets from different sites of the Level 2 carrier. The external routes maintained by a Level 2 carrier are exchanged through BGP sessions established between related routes of the Level 2 carrier. This can greatly reduce the number of routes maintained by the Level 1 carrier network.

II. Implementation of carrier’s carrier

Compared to the common MPLS L3VPN, the carrier’s carrier is different mainly because a CE of a Level 2 carrier accesses a PE of the Level 1 carrier:

l If the PE of the Level 1 carrier and the CE of the Level 2 carrier are in a same AS, configure IGP and LDP between them.

l If the PE of the Level 1 carrier and the CE of the Level 2 carrier are not in the same AS, configure MP-EBGP between them to label the routes exchanged.

In either case, you must enable MPLS on the CE of the Level 2 carrier. Moreover, The CE holds the VPN routes of the Level 2 carrier, but it does not advertise the routes to the PE of the Level 1 carrier; it only exchanges the routes with other PEs of the Level 2 carrier.

A Level 2 carrier can be an ordinary ISP or an MPLS L3VPN service provider.

When the Level 2 carrier is an ordinary ISP, its PEs run IGP to communicate with the CEs, rather than MPLS. As shown in Figure 1-7, PE 3 and PE 4 exchange VPN routes of the Level 2 carrier through IBGP sessions.

Figure 1-7 Scenario where the Level 2 carrier is an ISP

When the Level 2 carrier is an MPLS L3VPN service provider, its PEs need to run IGP and LDP to communicate with CEs. As shown in Figure 1-8, PE 3 and PE 4 exchange VPN routes of the Level 2 carrier through MP-IBGP sessions.

Figure 1-8 Scenario where the Level 2 carrier is an MPLS L3VPN service provider

& Note:

On an S9500 Series routing switch, an LPU with a suffix of C does not support the carrier’s carrier feature.

1.1.7 Multi-AS VPN

In some networking scenarios, multiple sites of a VPN may be connected to multiple ISPs in different ASs, or to multiple ASs of an ISP. Such an application is called multi-AS VPN.

RFC 2547bis presents three inter-provider VPN solutions:

l VRF-to-VRF: ASBRs manage VPN routes between them through VLAN interfaces. This solution is also called inter-provider VPN option A.

l EBGP advertisement of labeled VPN-IPv4 routes: ASBRs advertise labeled VPN-IPv4 routes to each other through MP-EBGP. This solution is also called inter-provider VPN option B.

l Multi-hop EBGP advertisement of labeled VPN-IPv4 routes: PEs advertise labeled VPN-IPv4 routes to each other through MP-EBGP. This solution is also called inter-provider VPN option C.

The following describes these three solutions.

I. Inter-provider VPN option A

In this kind of solution, PEs of two ASs are directly connected and each PE is also the ASBR of its AS.

The PEs acting as ASBRs are connected through multiple VLAN interfaces. Each of them treats the other as a CE of its own and advertises IPv4 routes through conventional EBGP. Within an AS, packets are forwarded using two-level label forwarding as VPN packets. Between ASBRs, conventional IP forwarding is used.

Ideally, each inter-provider VPN has a pair of VLAN interfaces to exchange VPN routing information.

Figure 1-9 Network diagram for inter-provider VPN option A

This kind of solution is easy to carry out because no special configuration is required on the PEs acting as the ASBRs.

However, it has limited scalability because the PEs acting as the ASBRs have to manage all the VPN routes and create VPN instances on a per-VPN basis. This leads to excessive VPN-IPv4 routes on the PEs. Moreover, the requirement to create a separate VLAN interface for each VPN also calls for higher performance of the PEs.

II. Inter-provider VPN option B

In this kind of solution, two ASBRs use MP-EBGP to exchange labeled VPN-IPv4 routes that they have obtained from the PEs in their respective ASs.

As shown in Figure 1-10, the routes are advertised through the following steps:

1) PEs in AS 100 advertise labeled VPN-IPv4 routes to the ASBR PE of AS 100 or the route reflector (RR) for the ASBR PE through MP-IBGP.

2) The ASBR PE advertises labeled VPN-IPv4 routes to the ASBR PE of AS 200 through MP-EBGP.

3) The ASBR PE of AS 200 advertises labeled VPN-IPv4 routes to PEs in AS 200 or to the RR for the PEs through MP-IBGP.

The ASBRs must perform the special processing on the labeled VPN-IPv4 routes, which is also called ASBR extension method.

Figure 1-10 Network diagram for inter-provider VPN option B

In terms of scalability, inter-provider VPN option B is better than option A.

When adopting MP-EBGP method, note that:

l ASBRs perform no VPN target filtering on VPN-IPv4 routes that they receive from each other. Therefore, the ISPs in different ASs that exchange VPN-IPv4 routes need to agree on the route exchange.

l VPN-IPv4 routes are exchanged only between VPN peers. A VPN user can exchange VPN-IPv4 routes neither with the public network nor with MP-EBGP peers with whom it has not reached agreement on the route exchange.

III. Inter-provider VPN option C

The above two kinds of solutions can satisfy the needs for inter-provider VPNs. However, they require that the ASBRs maintain and advertise VPN-IPv4 routes. When every AS needs to exchange a great amount of VPN routes, the ASBRs may become bottlenecks hindering network extension.

One way to solve the above problem is to make PEs directly exchange VPN-IPv4 routes without the participation of ASBRs:

l Two ASBRs advertise labeled IPv4 routes to PEs in their respective ASs through MP-IBGP.

l The ASBRs neither maintain VPN-IPv4 routes nor advertise VPN-IPv4 routes to each other.

l An ASBR maintains labeled IPv4 routes of the PEs in the AS and advertises them to the peers in the other ASs. The ASBR of an AS also advertises labeled IPv4 routes. Thus, an LSP is established between the ingress PE and egress PE.

l Between PEs of different ASs, Multi-hop EBGP connections are established to exchange VPN-IPv4 routes.

Figure 1-11 Network diagram for inter-provider VPN option C

To improve the scalability, you can specify an RR in each AS, making it maintain all VPN-IPv4 routes and exchange VPN-IPv4 routes with PEs in the AS. The RRs in two ASs establish an inter-provider VPNv4 connection to advertise VPN-IPv4 routes, as shown in Figure 1-12.

Figure 1-12 Network diagram for inter-provider VPN option C using RRs

1.1.8 HoVPN

I. Background

1) Hierarchical model and plane model

In MPLS L3VPN solutions, PEs are the key devices. They provide two functions:

l User access. This means that the PEs must have a large amount of interfaces.

l VPN route managing and advertising, and user packet processing. These require that a PE must have a large-capacity memory and high forwarding capability.

Most of the current network schemes use the typical hierarchical architecture. For example, the MAN architecture contains typically three layers, namely, the core layer, convergence layer, and access layer. From the core layer to the access layer, the performance requirements on the devices reduce while the network expands.

MPLS L3VPN, on the contrary, is a plane model where performance requirements are the same for all PEs. If a certain PE has limited performance or scalability, the performance or scalability of the whole network is influenced.

Due to the above difference, you are faced with the scalability problem when deploying PEs at any of the three layers. Therefore, the plane model is not applicable to the large-scale VPN deployment.

2) HoVPN

To solve the scalability problem of the plane model, MPLS L3VPN must transition to the hierarchical model.

In MPLS L3VPN, hierarchy of VPN (HoVPN) was proposed to meet that requirement. With HoVPN, the PE functions can be distributed among multiple PEs, which take different roles for the same functions and form a hierarchical architecture.

As in the typical hierarchical network model, HoVPN has different requirements on the devices at different layers of the hierarchy.

II. Implementation of HoVPN

1) Basic architecture of HoVPN

Figure 1-13 Basic architecture of HoVPN

As shown in Figure 1-13, devices directly connected to CEs are called underlayer PEs (UPEs) or user-end PEs, whereas devices that are connected with UPEs and are in the internal network are called superstratum PEs (SPE) or service provider-end PEs.

The hierarchical PE consists of multiple UPEs and SPEs, which function together as a traditional PE.

& Note:

With the HoVPN solution, PE functions are implemented hierarchically. Hence, the solution is also called hierarchy of PE (HoPE).

UPEs and SPEs play different roles:

l A UPE allows user access. It maintains the routes of the VPN sites that are directly connected with it, It does not maintain the routes of the remote sites in the VPN, or only maintains their summary routes. A UPE assigns inner labels to the routes of its directly connected sites, and advertises the labels to the SPE along with VPN routes through MP-BGP.

l An SPE manages and advertises VPN routes. It maintains all the routes of the VPNs connected through UPEs, including the routes of both the local and remote sites. An SPE does not advertise routes of the remote sites to UPEs; it only advertises to UPEs the default routes of VPN instances or summary routes along with labels.

Different roles mean different requirements:

l SPE: An SPE is required to have large-capacity routing table, high forwarding performance, and fewer interface resources.

l UPE: A UPE is required to have small-capacity routing table, low forwarding performance, but higher access capability.

HoVPN takes full use of both the high performance of SPEs and the high access capability of UPEs.

Note that the concepts of SPE and UPE are relative. In the hierarchical PE architecture, a PE may be the SPE of its underlayer PEs and a UPE of its SPE at the same time.

The HoPE and common PEs can coexist in an MPLS network.

2) SPE-UPE

The MP-BGP running between SPE and UPE can be either MP-IBGP or MP-EBGP. Which one to use depends on whether the UPE and SPE belong to a same AS.

With MP-IBGP, in order to advertise routes between IBGP peers, the SPE acts as the RR and advertises routes from IBGP peer UPE to IBGP peer SPE. However, it does not act as the RR of the other PEs.

3) Recursion and extension of HoVPN

HoVPN supports HoPE recursion:

l A HoPE can act as a UPE to form a new HoPE with an SPE.

l A HoPE can act as an SPE to form a new HoPE with multiple UPEs.

l HoVPN supports multi-level recursion.

With recursion of HoPEs, a VPN can be extended infinitely in theory.

Figure 1-14 Recursion of HoPEs

Figure 1-14 shows a three-level HoPE. The PE in the middle is called the middle-level PE (MPE). MP-BGP runs between SPE and MPE, as well as between MPE and UPE.

& Note:

The term of MPE does not really exist in a HoVPN model. It is used here just for the convenience of description.

MP-BGP advertises all the VPN routes of the UPEs to the SPEs, but advertises only the default routes of the VPN instance of the SPEs to the UPEs.

The SPE maintains the VPN routes of all sites in the HoVPN, while each UPE maintains only VPN routes of its directly connected sites. The number of routes maintained by the MPE is between the above two.

1.1.9 OSPF VPN Extension

& Note:

This section focuses on the OSPF VPN extension. For more information about OSPF, refer to the OSPF Configuration.

I. OSPF multi-instance on PE

OSPF is a prevalent IGP protocol. In many cases, VPN clients are connected through BGP peers, and the clients often run OSPF. Running OSPF between PEs and CEs can simplify the configuration and management of the CEs, because the CEs only need to support OSPF. In addition, if the customers require MPLS L3VPN services through conventional OSPF backbone, using OSPF between PEs and CEs can simplify the transition.

For OSPF to run between CEs and PEs, the PEs must support multiple OSPF instances. Each OSPF instance must correspond to a VPN instance and have its own interface and routing table.

The following describes details of OSPF configuration between PEs and CEs.

1) Configuration of OSPF areas between PEs and CEs

The OSPF area between a PE and a CE can be either a non-backbone area or a backbone area.

In the OSPF VPN extension application, the MPLS VPN backbone is considered the backbone area (area 0). Since OSPF requires that the backbone area must be contiguous, the area 0 of each VPN site must be connected with the MPLS VPN backbone.

That is, if a VPN site contains an OSPF area 0, the PE connected with the CE must be connected with the area 0 in this VPN site through an area 0 (the virtual link can be used for logical connection).

2) BGP/OSPF interaction

With OSPF running between PEs and CEs, PEs advertise VPN routes to each other through BGP and to CEs through OSPF.

With conventional OSPF, two sites are considered to be in different ASs even if they belong to the same VPN. Therefore, the routes that one site learns are advertised to the other as external routes. This results in higher OSPF traffic and network management problems that should have been avoided otherwise.

Currently, OSPF supports multiple instances and therefore can address the above problems. Properly configured, OSPF sites are considered directly connected, and PEs can exchange OSPF routing information as they are using dedicated lines. This improves the network management and makes OSPF applications more effective.

As shown in Figure 1-15, PE 1 and PE 2 are connected through the MPLS backbone, while CE 11, CE 21, and CE 22 belong to VPN 1. Assumes that all the devices in the figure belong to the same AS, that is, CE 11, CE 21, and CE 22 belong to the same OSPF domain. The advertisement procedure of VPN 1 routes is as follows:

l At first, PE 1 redistributes OSPF routes from CE 11 into BGP.

l Then, PE 1 advertises the VPN routes to PE 2 through BGP.

l Finally, PE 2 redistributes the BGP VPN routes into OSPF and advertises them to CE 21 and CE 22.

Figure 1-15 Application of OSPF in VPN

With the standard BGP/OSPF interaction, PE 2 advertises the BGP VPN routes to CE 21 and CE 22 through Type 5 LSAs (ASE LSAs). However, CE 11, CE 21, and CE 22 belong to the same OSPF domain, and the route advertisement between them should use Type 3 LSAs (inter-provider routes).

To solve the above problems, PE uses an extended BGP/OSPF interaction process called BGP/OSPF interoperability to advertise routes from one site to another, differentiating the routes from real AS-External routes. The process requires that extended BGP community attributes carry the information for identifying the OSPF attributes.

It is required that each OSPF domain has a configurable domain ID. It is recommended to configure for all OSPF instances in the network related to each VPN instance the same domain ID, or adopt the default ID. Thus, the system can know that all VPN routes with the same domain ID are from the same VPN instance.

3) Routing loop detection

If OSPF runs between CEs and PEs and a VPN site is connected to multiple PEs, when a PE advertises the BGP VPN routes learnt from MPLS/BGP to the VPN site through LSAs, the LSAs may be received by another PE, resulting in a routing loop.

To avoid routing loops, when creating Type 3 LSAs, the PE always sets the flag bit DN for BGP VPN routes learnt from MPLS/BGP, regardless of whether the PE and the CEs are connected through the OSPF backbone. When performing route calculation, the OSPF process of the PE ignores the Type 3 LSAs whose DN bit is set.

If the PE needs to advertise to a CE the routes from other OSPF domains, it must indicate that it is the ASBR, and advertise the routes using Type 5 LSAs.

II. Sham link

Generally, BGP peers carry routing information on the MPLS VPN backbone through the BGP extended community attributes. The OSPF that runs on the remote PE can use the information to create Type 3 summary LSAs to be transmitted to the CEs. As shown in Figure 1-16, both site 1 and site 3 belong to VPN 1 and OSPF area 1. They are connected to different PEs, PE 1 and PE 2. There is an intra-area OSPF link called backdoor link between them. In this case, the route connecting the two sites through PEs is an inter-area route. It is not preferred by OSPF because its preference is lower than that of the intra-area route across the backdoor link.

Figure 1-16 Network diagram for sham link

To solve the problem, you can establish a sham link between the two PEs so that the routes between them over the MPLS VPN backbone become an intra-area route.

The sham link acts as an intra-area point-to-point link and is advertised through the Type 1 LSA. You can select a route between the sham link and backdoor link by adjusting the metric.

The sham link is considered the link between the two VPN instances with one endpoint address in each VPN instance. The endpoint address is a loopback interface address with a 32-bit mask in the VPN address space on the PE. Different sham links of the same OSPF process can share an endpoint address, but that of different OSPF processes cannot.

BGP advertises the endpoint addresses of sham links as VPN-IPv4 addresses. A route across the sham link cannot be redistributed into BGP as a VPN-IPv4 route.

A sham link can be configured in any area. You need to configure it manually. In addition, the local VPN instance must have a route to the destination of the sham link.

III. Multi-VPN-Instance CE

Multiple OSPF instances usually run on PEs. A routing device on a LAN that runs multiple OSPF instances is called a multi-VPN-instance CE. Compared with the OSPF multi-instance on PEs, a multi-VPN-instance CE does not need to support the BGP/OSPF interoperability.

Multi-VPN-instance CEs are used to solve the security problem of LANs at a lower cost.

It is hard to implement the complete separation of services on LANs with traditional routing devices. Currently, a routing device supports multiple OSPF processes, which can belong to the public network or a VPN instance. Therefore, you can run multiple OSPF processes on a routing device and bind them to different VPN instances.

In practice, you can create OSPF instances for different services to separate services and ensure their security.

1.1.10 BGP AS Number Substitution

Since BGP detects routing loops by AS number, if EBGP runs between PEs and CEs, you must assign different AS numbers to geographically different sites to ensure correct transmission of the routing information.

The BGP AS number substitution function allows physically dispersed CEs to use the same AS number. The function is a BGP outbound policy and functions on routes to be advertised.

With the BGP AS number substitution function, when a PE advertises a route to a CE of the specified peer, if an AS number identical to that of the CE exist in the AS_PATH of the route, it will be replaced with that of the PE.

& Note:

After you enable the BGP AS number substitution function, the PE re-advertises all routing information to the connected CEs in the peer group, performing BGP AS number substitution based on the above principle.

Figure 1-17 Application of BGP AS number substitution

In Figure 1-17, both CE 1 and CE 2 use the AS number of 800. AS number substitution is enabled on PE 2 for CE 2. Before advertising updates received from CE 1 to CE 2, PE 2 finds that an AS number in the AS_PATH is the same as that of CE 2 and hence substitutes its own AS number 100 for the AS number. In this way, CE 2 can normally receive the routing information from CE 1.

AS number substitution also applies to a PE connecting multiple CEs through different interfaces, such as PE 2 in Figure 1-17, which connects CE 2 and CE 3.

& Note:

For a multi-homed CE, that is, a CE connected with multiple PEs, the BGP AS number substitution function must be used in combination with the site-of-origin (SOO) function. Otherwise, routing loops may appear.

1.2 MPLS L3VPN Configuration Task List

Task	Remarks
Configuring VPN Instances	Required
Configuring Basic MPLS L3VPN	Required
Configuring Inter-Provider VPN	Optional Configure it as needed
Configuring HoVPN	Optional Configure it as needed
Configuring OSPF Sham Link	Optional Configure it as needed
Configuring Multi-VPN-instance CE	Optional Configure it as needed
Configuring BGP AS Number Substitution	Optional Configure it as needed

1.3 Configuring VPN Instances

VPN instances are used to isolate VPN routes from public network routes. Configuring VPN instances is required in all MPLS L3VPN networking schemes.

In addition, routes of a VPN instance are isolated from those of another. This feature allows VPN instances to be used in networking schemes other than MPLS L3VPNs.

All VPN instance configurations are on PEs.

1.3.1 Creating a VPN Instance

A VPN instance is associated with a site, rather than a VPN. It is a collection of the VPN membership and routing rules of its associated site.

A VPN instance takes effect only after you configure an RD for it. Before configuring an RD for a VPN instance, you can configure no parameters for the instance other than a description.

A VPN instance description is a piece of descriptive information about the VPN instance. You can use it to keep information such as the relationship of the VPN instance with a VPN.

Follow these steps to create and configure a VPN instance:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Create a VPN instance and enter VPN instance view	ip vpn-instance vpn-instance-name	Required No VPN instance exists by default.
Configure an RD for the VPN instance	route-distinguisher route-distinguisher	Required
Configure a description for the VPN instance	description text	Optional A VPN instance has no description by default.

1.3.2 Associating a VPN Instance with an Interface

After creating and configuring a VPN instance, you associate the VPN instance with the interface for connecting CEs.

Follow these steps to associate a VPN instance with an interface:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter interface view	interface interface-type interface-number	—
Associate the current interface with the VPN instance	ip binding vpn-instance vpn-instance-name	Required No VPN instance is associated with an interface by default.

& Note:

When configured on an interface, the ip binding vpn-instance command clears the IP address of the interface. Therefore, you must re-configure the IP address of the interface after configuring the command.

1.3.3 Configuring Route Related Attributes of a VPN Instance

The control process of VPN route advertisement is as follows:

l When a VPN route learned from a CE gets redistributed into BGP, BGP associates it with a VPN target extended community attribute list, which is usually the export target attribute of the VPN instance associated with the CE.

l The VPN instance determines which routes it can accept and redistribute according to the import-extcommunity in the VPN target.

l The VPN instance determines how to change the VPN targets attributes for routes to be redistributed according to the export-extcommunity in the VPN target.

Follow these steps to configure route related attributes of a VPN instance

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter VPN instance view	ip vpn-instance vpn-instance-name	—
Configure VPN target extended communities for the VPN instance	vpn-target vpn-target&<1-8> [ both \| export-extcommunity \| import-extcommunity ]	Required
Configure the maximum number of routes for the VPN instance	routing-table limit number { warn-threshold \| simply-alert }	Optional By default, there is no limit to the number of routes.
Specify the import routing policy for the current VPN instance	import route-policy route-policy	Optional By default, all routes permitted by the import target attribute can be redistributed into the VPN instance.
Specify the export routing policy for the current VPN instance	export route-policy route-policy	Optional By default, all VPN instance routes permitted by the export target attribute can be redistributed.

& Note:

l A single vpn-target command can configure up to eight VPN targets. You can configure up to 20 VPN targets for a VPN instance.

l Before associating a routing policy with a VPN instance, you must create the routing policy at first. Otherwise, the default routing policy is used.

l Change of the limit on the the number of routes in a VPN instance (by using the routing-table limit command) does not affect the existing routing table. To make the change take effect immediately, you need to restart the routing protocol or shutdown and then undo shutdown the relevant interfaces.

1.3.4 Configuring a Tunneling Policy of a VPN Instance

I. Configuring a tunneling policy

Follow these steps to configure a tunneling policy:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Create a tunneling policy and enter tunneling policy view	tunnel-policy tunnel-policy-name	Required
Specify the priorities of tunnels and the number of tunnels for load balancing	tunnel select-seq { cr-lsp \| lsp }* load-balance-number number	Required By default, the LSP tunnel is used and the number of tunnels for load balancing is 1.

& Note:

When configuring tunnel priorities using the tunnel select-seq command, the tunnel type closer to the select-seq keyword has a higher priority.

II. Associating a tunneling policy with the VPN instance

Follow these steps to associate a tunneling policy with the VPN instance:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter VPN instance view	ip vpn-instance vpn-instance-name	Required
Associate a tunneling policy with the VPN instance	tnl-policy tunnel-policy-name	Required By default, the LSP tunnel is used and the number of tunnels for load balancing is 1.

& Note:

Create the tunneling policy before associating it with the VPN instance. Otherwise, the default policy will be used.

1.4 Configuring Basic MPLS L3VPN

This section describes how to configure a simple MPLS L3VPN, where only one carrier is involved, the MPLS backbone is not inter-provider, and none of the PEs or CEs functions as a PE and a CE at the same time.

Some special MPLS L3VPN networking scenarios such as HoVPN, multi-role host, and inter-provider VPN require additional configurations. For more information, refer to the related sections in this chapter.

In configuring MPLS L3VPN, the key task is to manage the advertisement of VPN routes on the MPLS backbone and includes the management of route advertisement between PEs and CEs and that between PEs.

As for the route exchange between a PE and a CE, you can configure static routes, multiple RIP instances, multiple OSPF instances, multiple IS-IS instances, or BGP according to the networking situations. MP-IBGP is adopted between PEs.

1.4.1 Configuration Prerequisites

Before configuring basic MPLS L3VPN, complete these tasks:

l Configure IGP for the MPLS backbone (PEs and Ps) to achieve IP connectivity

l Configure MPLS basic capability for the MPLS backbone (PEs and Ps)

l Configure MPLS LDP for the MPLS backbone (PEs and Ps) so that LDP LSPs can be established

l On CEs, configure the IP addresses of the interfaces for accessing the PEs

1.4.2 Configuring a VPN Instance

Follow these steps to configure a VPN instance:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Create a VPN instance and enter VPN instance view	ip vpn-instance vpn-instance-name	Required No VPN instance exists by default.
Configure an RD for the VPN instance	route-distinguisher route-distinguisher	Required
Associate the current VPN instance with one or more VPN targets	vpn-target vpn-target&<1-8> [ both \| export-extcommunity \| import-extcommunity ]	Required
Return to system view	quit	—
Enter interface view	interface interface-type interface-number	—
Associate the current interface with the VPN instance	ip binding vpn-instance vpn-instance-name	Required By default, an interface is associated with no VPN instance.

1.4.3 Configuring Route Advertisement between PE and CE

Route advertisement between PE and CE can depend on static routes, RIP, OSPF, IS-IS, or EBGP. You may choose one as needed.

I. Configuring static routes between PEs and CEs

Follow these steps to configure static routes between PEs and CEs:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Configure static routes for a specified VPN instance	ip route-static dest-address { mask \| mask-length } { gateway-address \| interface-type interface-number [ gateway-address ] \| vpn-instance d-vpn-instance-name gateway-address } [ preference preference-value ] [ tag tag-value ] [ description description-text ]	Required
Configure static routes for a specified VPN instance	ip route-static vpn-instance s-vpn-instance-name&<1-6> dest-address { mask \| mask-length } { gateway-address [ public ] \| interface-type interface-number [ gateway-address ] \| vpn-instance d-vpn-instance-name gateway-address } [ preference preference-value ] [ tag tag-value ] [ description description-text ]	Required

& Note:

Perform this configuration on the PEs. The configuration method on the CEs is the same for configuring ordinary static routes.

II. Configuring RIP between PE and CE

A RIP process belongs to only one VPN instance. If you run a RIP process without binding it to a VPN instance, the process is considered a public network process.

Follow these steps to configure RIP between PE and CE:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Create a RIP instance between PE and CE and enter RIP view	rip [ process-id ] vpn-instance vpn-instance-name	Required

& Note:

l Perform this configuration on the PEs. Only conventional RIP is required on CEs.

l For description and detailed configuration about RIP, refer to RIP Configuration in IP Routing Volume.

III. Configuring OSPF between PE and CE

An OSPF process that is bound to a VPN instance does not use the public network router ID configured in system view. Therefore, you need to specify the router ID when starting a process or to configure the IP address for at least one interface of the VPN instance.

An OSPF process belongs to only one VPN instance. If you run an OSPF process without binding it to a VPN instance, the process is considered a public network process.

Follow these steps to configure OSPF between PE and CE:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Create an OSPF instance between PE and CE and enter the OSPF view	ospf [ process-id ] [ router-id router-id ] [ vpn-instance vpn-instance-name ]	Required
Configure the OSPF domain ID	domain-id domain-id [ secondary ]	Optional 0 by default

& Note:

l Perform the configurations on PEs. Only conventional OSPF is required on CEs.

l After a VPN instance is deleted, all related OSPF processes are deleted at the same time.

An OSPF process can be configured with only one domain ID. Domain IDs of different OSPF processes are independent of each other.

All OSPF processes of a VPN must be configured with the same domain ID for routes to be correctly advertised, while OSPF processes on PEs in different VPNs can be configured with domain IDs as desired.

The domain ID of an OSPF process is included in the routes generated by the process. When an OSPF route is injected into BGP, the OSPF domain ID is included in the BGP VPN route and delivered as a BGP extended community attribute.

& Note:

l For description and detailed configuration about OSPF, refer to OSPF Configuration in IP Routing Volume.

l The configuration change made by the domain-id domain-id [ secondary ] command does not take effect immediately. You need to configure the reset ospf command to bring it into effect.

IV. Configuring IS-IS between PE and CE

An IS-IS process belongs to only one VPN instance. If you run a IS-IS process without binding it to a VPN instance, the process is considered a public network process.

Follow these steps to configure IS-IS between PE and CE:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Create an IS-IS instance between PE and CE and enter IS-IS view	isis [ process-id ] vpn-instance vpn-instance-name	Required

& Note:

l After configuring an IS-IS instance, you must start IS-IS by using the same method for starting a common IS-IS process.

l For description and detailed configuration about IS-IS, refer to IS-IS Configuration in IP Routing Volume.

V. Configuring EBGP Between PE and CE

1) On a PE

Follow these steps to configure EBGP between PE and CE on a PE:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	—
Enter BGP VPN instance view	ipv4-family vpn-instance vpn-instance-name	Required
Configure the CE as the VPN peer	peer { group-name \| ip-address } as-number as-number	Required
Inject the routes of the local CEs	import-route protocol [ process-id ] [ med med-value \| route-policy route-policy-name ]*	Required A PE needs to inject the routes of the local CEs into its VPN routing table so that it can advertise them to the peer PE.
Configure BGP to filter routes to be advertised	filter-policy { acl-number \| ip-prefix ip-prefix-name } export [ direct \| isis process-id \| ospf process-id \| rip process-id \| static ]	Optional By default, BGP does not filter routes to be advertised.
Configure BGP to filter received routes	filter-policy { acl-number \| ip-prefix ip-prefix-name } import	Optional By default, BGP does not filter received routes.
Allow the local AS number to appear in the AS_PATH attribute of a received route and set the maximum number of repetitions	peer { group-name \| ip-address } allow-as-loop [ number ]	Optional For the hub and spoke networking scheme

& Note:

Normally, BGP detects routing loops by AS number. In the hub and spoke networking scheme, however, with EBGP running between PE and CE, the routing information the PE advertises to a CE carries the number of the AS where the PE resides. Therefore, the route updates that the PE receives from the CE also include the number of the AS where the PE resides. This causes the PE unable to receive the route updates. In this case, routing loops must be allowed.

2) On a CE

Follow these steps to configure EBGP between PE and CE on a CE:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	Required
Configure the PE as the peer	peer { group-name \| ip-address } as-number as-number	Required
Configure the route advertisement behavior	import-route protocol [ process-id ] [ med med-value \| route-policy route-policy-name ] *	Optional A CE needs to advertise its routes to the connected PE so that the PE can advertise them to the peer CE.

& Note:

l Exchange of BGP routes for a VPN instance is the same as that of ordinary BGP routes.

l The configuration task in BGP instance view is the same as that in BGP view. For detailed information, refer to BGP Configuration and BGP Commands in IP Routing Volume.

l For information about BGP peer and peer group configuration, refer to BGP Configuration and BGP Commands in IP Routing Volume. This chapter does not differentiate between peer and peer group.

1.4.4 Configuring Route Advertisement Between PEs

Follow these steps to configure route advertisement between PEs:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	Required
Configure the remote PE as the peer	peer { group-name \| ip-address } as-number as-number	Required
Specify the source interface for route updates	peer { group-name \| ip-address } connect-interface interface-type interface-number	Required By default, BGP uses the source interface of the optimal route update packet.
Enter BGP-VPNv4 subaddress family view	ipv4-family vpnv4 [ unicast ]	Required
Enable the exchange of BGP-VPNv4 routing information with the specified peer	peer { group-name \| ip-address } enable	Required By default, BGP peers exchange only IPv4 routing information.

1.4.5 Configuring Routing Features for BGP VPNv4 Subaddress Family

With BGP VPNv4 subaddress family, there are a variety of routing features that are the same as those for BGP IPv4 unicast routing. You can select any of the features as required.

I. Configuring common routing features for all types of subaddress families

For VPN applications, BGP address families include BGP VPN-IPv4 address family, BGP-L2VPN address family, and VPLS address family. Every command in the following table has the same function on BGP routes for each type of the address families.

Follow these steps to configure common routing features for all types of subaddress families:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	Required
Configure the remote PE as the peer	peer ip-address as-number as-number	Required
Specify the interface for TCP connection	peer ip-address connect-interface interface-type interface-number	Required
Enter address family view	ipv4-family vpnv4	Required Use one of the commands as needed.
	l2vpn-family
	vpls-family
Allow the local AS number to appear in the AS_PATH attribute of a received route and set the maximum number of repetitions	peer { group-name \| ip-address } allow-as-loop [ number ]	Optional
Enable a peer or peer group for an address family and enable the exchange of BGP routing information of the address family	peer { group-name \| ip-address } enable	Required By default, only IPv4 routing information is exchanged between BGP peers.
Add a peer into an existing peer group	peer ip-address group group-name	Optional
Configure the system to use the local address as the next hop of a route to be advertised to a specified peer or peer group	peer { group-name \| ip-address } next-hop-local	Optional
Configure the system to be the RR and set a peer or peer group as the client of the RR	peer { group-name \| ip-address } reflect-client	Optional By default, no RR or RR client is configured.
Enable VPN target filtering for received VPNv4 routes	policy vpn-target	Optional Enabled by default
Enable route reflection between clients	reflect between-clients	Optional Enabled by default
Specify the cluster ID of the RR	reflector cluster-id { cluster-id \| ip-address }	Optional Router ID of an RR in the cluster by default
Create an RR reflection policy	rr-filter extended-community-list-number	Optional

& Note:

For information about BGP-L2VPN address family and VPLS address family, refer to MPLS L2VPN Commands and VPLS Commands in MPLS VPN Volume.

II. Configuring specific routing features for BGP-VPNv4 subaddress family

Follow these steps to configure specific routing features for BGP-VPNv4 subaddress family:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	—
Configure the remote PE as the peer	peer ip-address as-number as-number	Required
Specify the interface for TCP connection	peer ip-address connect-interface interface-type interface-number	Required
Enter BGP-VPNv4 subaddress family view	ipv4-family vpnv4	—
Set the default value of the local preference	default local-preference value	Optional 100 by default
Set the default system metric	default med med-value	Optional 0 by default
Configure BGP to filter all or certain types of routes to be advertised	filter-policy { acl-number \| ip-prefix ip-prefix-name } export [ direct \| isis process-id \| ospf process-id \| rip process-id \| static ]	Optional By default, BGP does not filter routes to be advertised.
Configure BGP to filter received routes	filter-policy { acl-number \| ip-prefix ip-prefix-name } import	Optional By default, BGP does not filter received routes.
Configure the system to advertise community attributes to a peer or peer group	peer { group-name \| ip-address } advertise-community	Optional By default, no community attributes are advertised to any peer or peer group.
Specify to filter routes received from or to be advertised to a peer or peer group based on an AS_PATH list	peer { group-name \| ip-address } as-path-acl aspath-filter-number { import \| export }	Optional By default, no AS filtering list is applied to a peer or peer group.
Specify to advertise all default routes of a VPN instance to a peer or peer group	peer { group-name \| ip-address } default-route-advertise vpn-instance vpn-instance-name	By default, no default route is advertised to a peer or peer group.
Apply a filtering policy to a peer or peer group	peer { group-name \| ip-address } filter-policy acl-number { export \| import }	Optional By default, no filtering policy is applied to a peer or peer group.
Apply a route filtering policy based on IP prefix list to a peer or peer group	peer { group-name \| ip-address } ip-prefix prefix-name { export \| import }	Optional By default, no route filtering policy based on IP prefix list is applied to a peer or peer group.
Specify not to change the next hop of a route when advertising it to an EBGP peer	peer { group-name \| ip-address } next-hop-invariable	Optional By default, a device uses its address as the next hop when advertising a route to its EBGP peer.
Make BGP updates to be sent carry no private AS numbers	peer { group-name \| ip-address } public-as-only	Optional By default, a BGP update carries private AS numbers.
Apply a routing policy to a peer or peer group	peer { group-name \| ip-address } route-policy route-policy-name { export \| import }	Optional By default, no routing policy is applied to a peer or peer group.

& Note:

For information about BGP routing, refer to BGP Configuration in IP Routing Volume.

1.5 Configuring Inter-Provider VPN

If the MPLS backbone on which the VPN routes rely spans multiple ASs, you need to configure inter-provider VPN.

There are three inter-provider VPN solutions (refer to Multi-AS VPN). You can choose them as required.

1.5.1 Configuration Prerequisites

Before configuring inter-provider VPN, complete these tasks:

l Configuring IGP for the MPLS backbones in each AS to implement IP connectivity of the backbones in the AS

l Configuring basic MPLS capabilities for the MPLS backbones of each AS

l Configuring MPLS LDP for the MPLS backbones so that LDP LSPs can be established

l Configuring basic MPLS L3VPN for each AS

& Note:

When configuring basic MPLS L3VPN for each AS, specific configurations may be required on PEs or ASBR-PEs. This depends on the inter-provider VPN solution selected.

1.5.2 Configuring Inter-Provider VPN Option A

Inter-provider VPN option A applies to scenarios where the number of VPNs and that of VPN routes on the PEs are relatively small. It is simple to implement.

To configure inter-provider VPN option A, you only need to:

l Configure basic MPLS L3VPN on each AS.

l Configure each ASBR, taking the peer ASBR PE as its CE.

In other words, configure VPN instances for PEs and ASBR PEs respectively. The VPN instance for PE is used to allow CEs to access the network, while that for ASBR-PE is used to access its peer ASBR-PE.

Refer to Configuring Basic MPLS L3VPN.

& Note:

In the inter-provider VPN option A solution, for the same VPN, the VPN targets for the VPN instances of the PEs must match those for the VPN instances of the ASBR-PEs in the same AS. It is not required for PEs in different ASs.

1.5.3 Configuring Inter-Provider VPN Option B

Follow these steps to configure inter-provider VPN option B on ASBR PEs:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter interface view for the interface connecting to the remote ASBR-PE	interface interface-type interface-number	Required
Configure the IP address of the interface	ip address ip-address { mask \| mask-length }	Required
Return to system view	quit	—
Enter BGP view	bgp as-number	Required
Enter BGP-VPNv4 subaddress family view	ipv4-family vpnv4	Required
Disable VPN target filtering for VPNv4 routes	undo policy vpn-target	Required By default, PE performs VPN target filtering of the received VPNv4 routes. The routes surviving the filtering will be added to the routing table, and the others are discarded.

In the inter-provider VPN option B solution, the ASBR PEs need to maintain all VPNv4 routing information and advertise the information to peer ASBR PEs. In this case, the ASBR PEs must receive all VPNv4 routing information without performing VPN target filtering.

& Note:

In the inter-provider VPN option B solution, for the same VPN, the VPN targets for the VPN instances of the PEs must match those for the VPN instances of the ASBR-PEs in the same AS. This is true for PEs in different ASs.

Caution:

For inter-provider VPN option B, two configuration methods are available:

l Do not change the next hop on an ASBR. With this method, you still need to configure MPLS LDP between ASBRs.

l Change the next hop on an ASBR. With this method, MPLS LDP is not required between ASBRs.

Currently, only the second method is supported. Therefore, MP-EBGP routes will get their next hops changed by default before being redistributed to MP-IBGP. On conventional BGP, however, EBGP routes to be advertised to IBGP do not have their next hops changed by default. If the next hops need to be changed to the local addresses, you can configure the peer ip-address next-hop-local command.

1.5.4 Configuring Inter-Provider VPN Option C

I. Configuring the PEs

You need to establish ordinary IBGP peer relationship between PEs and ASBR PEs in an AS and MP-EBGP peer relationship between PEs of different ASs.

The PEs and ASBR PEs in an AS must be able to exchange labeled IPv4 routes.

Follow these steps to configure a PE for inter-provider VPN option C:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	Required
Configure the ASBR PE in the same AS as the IBGP peer	peer peer-address as-number as-number	Required
Enable the PE to exchange labeled IPv4 routes with the ASBR PE in the same AS	peer peer-address label-route-capability	Required
Configure the PE of another AS as the EBGP peer	peer peer-address as-number as-number	Required
Enter BGP-VPNv4 subaddress family view	ipv4-family vpnv4	Required
Enable the PE to exchange BGP VPNv4 routing information with the peer	peer peer-address enable	Required
Configure the PE not to change the next hop of a route when advertising it to the EBGP peer	peer peer-address next-hop-invariable	Optional Required only when RRs are used to advertise VPNv4 routes, where the next hop of a route advertised between RRs cannot be changed. Usually, this step is not needed.

II. Configuring the ASBR PEs

In the inter-provider VPN option C solution, an inter-provider VPN LSP is required, and the routes advertised between the relevant PEs and ASBRs must carry MPLS label information.

An ASBR-PE establishes common IBGP peer relationship with PEs in the same AS, and common EBGP peer relationship with the peer ASBR PE. All of them exchange labeled IPv4 routes.

The public routes carrying MPLS labels are advertised through MP-BGP. According to RFC 3107 “Carrying Label Information in BGP-4”, the label mapping information for a particular route is piggybacked in the same BGP update message that is used to distribute the route itself. This capability is implemented through BGP extended attributes and requires that the BGP peers can handle labeled IPv4 routes.

Follow these steps to configure an ASBR PE for inter-provider VPN option C:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	—
Configure each PE in the same AS as the IBGP peer	peer peer-address as-number as-number	Required
Enable the ASBR PE to exchange labeled IPv4 routes with the PEs in the same AS	peer peer-address label-route-capability	Required By default, the device does not advertise labeled routes to the IPv4 peer.
Configure the ASBR PE to change the next hop to itself when advertising routes to PEs in the same AS	peer peer-address next-hop-local	Required By default, a BGP speaker does not use its address as the next hop when advertising a route to its IBGP peer.
Configure the remote ASBR PE as the EBGP peer	peer peer-address as-number as-number	Required
Enable the ASBR PE to exchange labeled IPv4 routes with the peer ASBR PE	peer peer-address label-route-capability	Required By default, the device does not advertise labeled routes to the IPv4 peer.
Apply a routing policy to the routes advertised by peer ASBR PE	peer peer-address route-policy policy-name export	Required By default, no routing policy is applied to a peer or peer group.

III. Configuring the routing policy

After you configure and apply a routing policy on an ASBR PE, it:

l Assigns MPLS labels to the routes received from the PEs in the same AS before advertising them to the peer ASBR PE.

l Assigns new MPLS labels to the labeled IPv4 routes to be advertised to the PEs in the same AS.

l Does not advertise routes that match the routing policy but fail to be assigned with MPLS labels as common routes.

Which IPv4 routes are to be assigned with MPLS labels depends on the routing policy. Only routes that satisfy the criteria are assigned with labels. All the other routes are still common IPv4 routes.

Follow these steps to configure a routing policy for inter-provider VPN option C (between ASBR PEs):

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter routing policy view	route-policy policy-name permit node seq-number	Required
Configure the destination IP address match criteria of the routing information	if-match acl acl-number	Optional
Configure the device to assign labels to IPv4 routes	apply mpls-label	Required By default, an IPv4 route does not carry any label.

Follow these steps to configure a routing policy for inter-provider VPN option C (in the direction from ASBR to PE):

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter routing policy view	route-policy policy-name permit node seq-number	Required
Configure the destination IP address match criteria of the routing information	if-match acl acl-number	Optional
Configure the device to match IPv4 routes with labels	if-match mpls-label	Optional This step is recommended when you want the device to advertise IPv4 routes with labels through BGP extension in the direction from ASBR to PE
Configure the device to assign labels to IPv4 routes	apply mpls-label	Required By default, an IPv4 route does not carry any label.

& Note:

l When configuring a routing policy for inter-provider VPN option C, you are recommended to configure the destination IP address match criteria of the routing information to avoid possible conflicts with common IPv4 address families.

l For information about routing policy configuration, refer to Routing Policy Configuration in IP Routing Volume.

1.6 Configuring HoVPN

For hierarchical VPNs, you can adopt HoVPN to reduce the performance requirements for PEs.

1.6.1 Configuration Prerequisites

Before configuring HoVPN, complete these tasks:

l Configuring basic MPLS L3VPN

1.6.2 Configuring HoVPNs

Follow these steps to configure HoVPN:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	—
Enter BGP-VPNv4 subaddress family view	ipv4-family vpnv4	Required
Enable the exchange of BGP-VPNv4 routing information with a peer	peer { group-name \| ip-address } enable	Required
Specify a BGP peer or peer group as the UPE	peer { group-name \| ip-address } upe	Required
Specify to advertise default routes of a VPN instance to a UPE	peer { group-name \| ip-address } default-route-advertise vpn-instance vpn-instance-name	Optional By default, BGP does not advertise default routes to a VPNv4 peer.

With the peer default-route-advertise vpn-instance command configured, the SPE always advertises a default route using the local address as the next hop address to the UPE, regardless of whether the default route is present in the local routing table or not.

& Note:

l The default routes of a VPN instance can be advertised to only a BGP peer or peer group that is UPE.

l It is not recommended for an SPE to be connected to a CE directly. If an SPE must be directly connected with a CE, the VPN instance on the SPE and that on the UPE must be configured with different RDs.

1.7 Configuring OSPF Sham Link

The sham link is considered an OSPF intra-area route. It is used to ensure that the VPN traffic is transmitted over the backbone instead of the backdoor link between two CEs.

The source and destination addresses of the sham link must be loopback interface addresses with 32-bit masks. Besides, the loopback interfaces must be bound to the VPN instances and be advertised through BGP.

1.7.1 Configuration Prerequisites

Before configuring OSPF sham link, be sure to complete these tasks:

l Configuring basic MPLS L3VPN (OSPF is used between PE and CE)

l Configuring OSPF in the LAN where CEs reside

1.7.2 Configuring a Loopback Interface

Follow these steps to configure a loopback interface:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Create a loopback interface and enter loopback interface view	interface loopback interface-number	Required
Bind the loopback interface to VPN instance	ip binding vpn-instance vpn-instance-name	Required By default, an interface is associated with no VPN instance.
Configure the address of the loopback interface	ip address ip-address { mask \| mask-length }	Required

1.7.3 Advertising Routes of a Loopback Interface

Follow these steps to advertise routes of a loopback interface:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	Required
Enter BGP VPN instance view	ipv4-family vpn-instance vpn-instance-name	Required
Inject direct routes, that is, loopback host routes	import-route direct	Required

1.7.4 Configuring a Sham Link

Follow these steps to configure a sham link:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter OSPF view	ospf [ process-id \| router-id router-id \| vpn-instance vpn-instance-name ] *	Required You are recommended to configure the router-id argument.
Configure the route tag	route-tag tag-id	Required
Enter OSPF area view	area area-id	Required
Configure a sham link	sham-link source-ip-address destination-ip-address [ cost cost \| dead dead-interval \| hello hello-interval \| retransmit retrans-interval \| trans-delay delay \| simple [ cipher \| plain ] password1 \| { md5 \| hmac-md5 } key-id [ cipher \| plain ] password2 ] *	Required By default, no sham link is configured.

& Note:

l If you start OSPF but do not configure the router ID, the system will automatically elect one. However, the same election rules produce the same router ID. Therefore, you are recommended to configure the router ID when starting an OSPF process. For the election rules, refer to OSPF Configuration.

l If you configure multiple OSPF VPN instances but do not configure the route tag, the system will automatically create one based on the AS number configured. If you do not configure BGP, the tag will be 0. However, the same calculation rule produces the same tag, and hence the same tag will be created for multiple OSPF VPN instances on the same PE or PEs with the same AS number. Therefore, you are recommended to configure different tags for different OSPF VPN instance.

1.8 Configuring Multi-VPN-instance CE

Multi-VPN-instance CE is used in LANs. By configuring multiple OSPF instances on CEs, you can implement service isolation.

One OSPF process can belong to only one VPN instance; one VPN instance can run several OSPF processes.

1.8.1 Configuration Prerequisites

Before configuring multi-VPN-instance CE, complete these tasks:

l Configuring VPN instances

l Configuring the link layer and network layer protocols on related interfaces to ensure IP connectivity.

1.8.2 Configuration Procedure

Multi-VPN-instance CE can be regarded as a networking solution for implementing service isolation by route isolation. There is no special configuration required for a multi-VPN-instance CE, except that you need to enable the multi-VPN-instance CE function.

After you enable multi-VPN-instance CE, routing loop detection on the PE is disabled for route calculating to avoid route loss, and BGP/OSPF interoperability is disabled to save system resources.

Follow these steps to configure multi-VPN-instance CE:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter OSPF multi-instance view	ospf [ process-id \| router-id router-id \| vpn-instance vpn-instance-name ] *	Required
Enable multi-VPN-instance CE	vpn-instance-capability simple	Required Disabled by default

1.9 Configuring BGP AS Number Substitution

1.9.1 Configuration Prerequisites

Before configuring BGP AS number substitution, complete these tasks:

l Configuring basic MPLS L3VPN

l Configuring CEs at different sites to have the same AS number

1.9.2 Configuration Procedure

When CEs at different sites have the same AS number, you need to configure the BGP AS number substitution function to avoid route loss.

Follow these steps to configure the BGP AS number substitution function:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter BGP view	bgp as-number	Required
Enter BGP VPN instance view	ipv4-family vpn-instance vpn-instance-name	Required
Enable the BGP AS number substitution function	peer { ip-address \| group-name } substitute-as	Required Disabled by default

1.10 Displaying and Maintaining MPLS L3VPN

1.10.1 Resetting BGP Connections

When BGP configuration changes, you can use the soft reset function or reset BGP connections to make new configurations take effect. Soft reset requires that BGP peers have route refreshment capability (supporting Route-Refresh messages).

To do…	Use the command…	Remarks
Perform a soft reset of the BGP connections in a specified VPN instance	refresh bgp vpn-instance vpn-instance-name { ip-address \| all \| external \| group group-name } { export \| import }	Available in user view
Perform a soft reset of the BGP VPNv4 connections	refresh bgp vpnv4 { ip-address \| all \| external \| group group-name \| internal } { export \| import }	Available in user view
Reset BGP connections of a VPN instance	reset bgp vpn-instance vpn-instance-name { as-number \| ip-address \| all \| external \| group group-name }	Available in user view
Reset BGP VPNv4 connections	reset bgp vpnv4 { as-number \| ip-address \| all \| external \| internal \| group group-name }	Available in user view

1.10.2 Displaying and Maintaining MPLS L3VPN

To do…	Use the command…	Remarks
Display information about the routing table associated with a VPN instance	display ip routing-table vpn-instance vpn-instance-name [ verbose ]	Available in any view
Display information about a specified or all VPN instances	display ip vpn-instance [ instance-name vpn-instance-name \| verbose \| brief ]	Available in any view
Display information about the FIB of a VPN instance	display fib vpn-instance vpn-instance-name [ include text ]	Available in any view
Display statistics about the VPN instance forwarding table	display fib statistics vpn-instance	Available in any view
Display information about labeled routes in the BGP routing table	display bgp vpnv4 { all \| vpn-instance vpn-instance-name } routing-table label	Available in any view
Display information about a specified or all BGP VPNv4 peer group	display bgp vpnv4 { all \| vpn-instance vpn-instance-name } group [ group-name ]	Available in any view
Display information about BGP VPNv4 routes injected into a specified or all VPN instances	display bgp vpnv4 { all \| \| vpn-instance vpn-instance-name } network	Available in any view
Display BGP VPNv4 AS path information	display bgp vpnv4 { all \| vpn-instance vpn-instance-name } paths [ as-regular-expression ]	Available in any view
Display information about BGP VPNv4 peers	display bgp vpnv4 { all \| vpn-instance vpn-instance-name } peer [ group-name log-info \| ip-address { log-info \| verbose } \| verbose ]	Available in any view
Display all BGP VPNv4 routing information	display bgp vpnv4 all routing-table [ network-address [ { mask \| mask-length } [ longer-prefixes ] ] \| as-path-acl as-path-acl-number \| cidr \| community [ aa:nn ]&<1-13> [ no-export-subconfed \| no-advertise \| no-export ]* [ whole-match ] \| community-list { basic-community-list-number [ whole-match ] \| adv-community-list-number }&<1-16> \| different-origin-as \| regular-expression as-regular-expression \| statistic ]	Available in any view
Display the BGP VPNv4 routing information of a specified RD	display bgp vpnv4 route-distinguisher route-distinguisher routing-table [ network-address [ { mask-length \| mask-address } [ longer-prefixes ] ] \| as-path-acl as-path-acl-number \| cidr \| community [ aa:nn ]&<1-13> [ no-export-subconfed \| no-advertise \| no-export ]* [ whole-match ] \| community-list { basic-community-list-number [ whole-match ] \| adv-community-list-number }&<1-16> \| different-origin-as \| regular-expression as-regular-expression ]	Available in any view
Display the BGP VPNv4 routing information of a specified VPN instance	display bgp vpnv4 vpn-instance vpn-instance-name routing-table [ network-address [ { mask-length \| mask-address } [ longer-prefixes ] ] \| as-path-acl as-path-acl-number \| cidr \| community [ aa:nn ]&<1-13>[ no-export-subconfed \| no-advertise \| no-export ]* [ whole-match ] \| community-list { basic-community-list-number [ whole-match ] \| adv-community-list-number }&<1-16> \| dampened \| dampening parameter \| different-origin-as \| flap-info [ as-path-acl as-path-acl-number \| network-address [ mask [ longer-match ] \| mask-length [ longer-match ] ] \| regular-expression as-regular-expression ] \| peer ip-address { advertised-routes \| received-routes } \| regular-expression as-regular-expression \| statistic ]	Available in any view
Display information about OSPF sham links	display ospf [ process-id ] sham-link [ area area-id ]	Available in any view
Display information about a specified or all tunnel policies	display tunnel-policy { all \| policy-name tunnel-policy-name }	Available in any view
Clear the route flap dampening information of a VPN instance	reset bgp vpn-instance vpn-instance-name dampening [ network-address [ mask \| mask-length ]	Available in user view
Clear route flap history information about a BGP peer of a VPN instance	reset bgp vpn-instance vpn-instance-name ip-address flap-info reset bgp vpn-instance vpn-instance-name flap-info [ ip-address [ mask \| mask-length ] \| as-path-acl as-path-acl-number \| regexp as-path-regexp ]	Available in user view

1.11 MPLS L3VPN Configuration Example

1.11.1 Example for Configuring MPLS L3VPNs

I. Network requirements

l CE 1 and CE 3 belong to VPN A, while CE 2 and CE 4 belong to VPN B.

l VPN A uses VPN target attributes 111:1, while VPN B uses VPN target attributes 222:2. Users of different VPNs cannot access each other.

l The PEs and P device are switches that support MPLS, while the CEs are common Layer 3 switches.

II. Network diagram

Device	Interface	IP address	Device	Interface	IP address
CE 1	Vlan-int1	10.1.1.1/24	P	Loop0	2.2.2.9/32
PE 1	Loop0	1.1.1.9/32		Vlan-int1	172.2.1.1/24
	Vlan-int1	10.1.1.2/24		Vlan-int3	172.1.1.2/24
	Vlan-int3	172.1.1.1/24	PE 2	Loop0	3.3.3.9/32
	Vlan-int2	10.2.1.2/24		Vlan-int1	172.2.1.2/24
CE 2	Vlan-int1	10.2.1.1/24		Vlan-int2	10.3.1.2/24
CE 3	Vlan-int1	10.3.1.1/24		Vlan-int3	10.4.1.2/24
CE 4	Vlan-int1	10.4.1.1/24

Figure 1-18 Configure MPLS L3VPNs

III. Configuration procedure

1) Configure IGP on the MPLS backbone, enabling the PEs and the P device to communicate

# Configure PE 1.

[PE1] interface loopback 0

[PE1-LoopBack0] ip address 1.1.1.9 32

[PE1-LoopBack0] quit

[PE1] interface vlan-interface 3

[PE1-Vlan-interface3] ip address 172.1.1.1 24

[PE1- Vlan-interface3] quit

[PE1] ospf

[PE1-ospf-1] area 0

[PE1-ospf-1-area-0.0.0.0] network 172.1.1.0 0.0.0.255

[PE1-ospf-1-area-0.0.0.0] network 1.1.1.9 0.0.0.0

[PE1-ospf-1-area-0.0.0.0] quit

[PE1-ospf-1] quit

# Configure the P device.

[P] interface loopback 0

[P-LoopBack0] ip address 2.2.2.9 32

[P-LoopBack0] quit

[P] interface vlan-interface 3

[P-Vlan-interface3] ip address 172.1.1.2 24

[P- Vlan-interface3] quit

[P] interface vlan-interface 1

[P-Vlan-interface1] ip address 172.2.1.1 24

[P-Vlan-interface1] quit

[P] ospf

[P-ospf-1] area 0

[P-ospf-1-area-0.0.0.0] network 172.1.1.0 0.0.0.255

[P-ospf-1-area-0.0.0.0] network 172.2.1.0 0.0.0.255

[P-ospf-1-area-0.0.0.0] network 2.2.2.9 0.0.0.0

[P-ospf-1-area-0.0.0.0] quit

[P-ospf-1] quit

# Configure PE 2.

[PE2] interface loopback 0

[PE2-LoopBack0] ip address 3.3.3.9 32

[PE2-LoopBack0] quit

[PE2] interface vlan-interface 1

[PE2-Vlan-interface1] ip address 172.2.1.2 24

[PE2-Vlan-interface1] quit

[PE2] ospf

[PE2-ospf-1] area 0

[PE2-ospf-1-area-0.0.0.0] network 172.2.1.0 0.0.0.255

[PE2-ospf-1-area-0.0.0.0] network 3.3.3.9 0.0.0.0

[PE2-ospf-1-area-0.0.0.0] quit

[PE2-ospf-1] quit

After you complete the above configurations, OSPF adjacency should be established between PE 1, P, and PE 2. Issuing the display ospf peer command, you can see that the adjacency status is Full. Issuing the display ip routing-table command, you can see that the PEs have learned the loopback route of each other. The following takes PE 1 as an example:

[PE1] display ip routing-table

Routing Tables: Public

Destinations : 9 Routes : 9

Destination/Mask Proto Pre Cost NextHop Interface

1.1.1.9/32 Direct 0 0 127.0.0.1 InLoop0

2.2.2.9/32 OSPF 10 1 172.1.1.2 Vlan3

3.3.3.9/32 OSPF 10 2 172.1.1.2 Vlan3

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

172.1.1.0/24 Direct 0 0 172.1.1.1 Vlan3

172.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

172.2.1.0/24 OSPF 10 1 172.1.1.2 Vlan3

[PE1] display ospf peer

OSPF Process 1 with Router ID 1.1.1.9

Neighbor Brief Information

Area: 0.0.0.0

Router ID Address Pri Dead-Time Interface State

172.1.1.2 172.1.1.2 1 38 Vlan3 Full/DR

2) Configure MPLS basic capability and MPLS LDP on the MPLS backbone to establish LDP LSPs

# Configure PE 1.

[PE1] mpls lsr-id 1.1.1.9

[PE1] mpls

[PE1-mpls] quit

[PE1] mpls ldp

[PE1-mpls-ldp] quit

[PE1] interface vlan-interface 3

[PE1-Vlan-interface3] mpls

[PE1-Vlan-interface3] mpls ldp

[PE1-Vlan-interface3] quit

# Configure the P device.

[P] mpls lsr-id 2.2.2.9

[P] mpls

[P-mpls] quit

[P] mpls ldp

[P-mpls-ldp] quit

[P] interface vlan-interface 3

[P-Vlan-interface3] mpls

[P-Vlan-interface3] mpls ldp

[P-Vlan-interface3] quit

[P] interface vlan-interface 1

[P-Vlan-interface1] mpls

[P-Vlan0interface1] mpls ldp

[P-Vlan-interface1] quit

# Configure PE 2.

[PE2] mpls lsr-id 3.3.3.9

[PE2] mpls

[PE2-mpls] quit

[PE2] mpls ldp

[PE2-mpls-ldp] quit

[PE2] interface vlan-interface 1

[PE2-Vlan-interface1] mpls

[PE2-Vlan-interface1] mpls ldp

[PE2-Vlan-interface1] quit

After you complete the above configurations, LDP sessions should be established between PE 1, P, and PE 2. Issuing the display mpls ldp session command, you can see that the Session State field has a value of Operational. Issuing the display mpls ldp lsp command, you can see that the LSPs established by LDP. The following takes PE 1 as an example:

[PE1] display mpls ldp session

LDP Session(s) in Public Network

Total number of sessions: 1

----------------------------------------------------------------

Peer-ID Status LAM SsnRole FT MD5 KA-Sent/Rcv

---------------------------------------------------------------

2.2.2.9:0 Operational DU Passive Off Off 5/5

---------------------------------------------------------------

LAM : Label Advertisement Mode FT : Fault Tolerance

[PE1] display mpls ldp lsp

LDP LSP Information

------------------------------------------------------------------

SN DestAddress/Mask In/OutLabel Next-Hop In/Out-Interface

------------------------------------------------------------------

1 1.1.1.9/32 3/NULL 127.0.0.1 Vlan3/InLoop0

2 2.2.2.9/32 NULL/3 172.1.1.2 -------/Vlan3

3 3.3.3.9/32 NULL/1024 172.1.1.2 -------/Vlan3

------------------------------------------------------------------

A '*' before an LSP means the LSP is not established

A '*' before a Label means the USCB or DSCB is stale

3) Configure VPN instances on PEs to allow CEs to access

# Configure PE 1.

[PE1] ip vpn-instance vpna

[PE1-vpn-instance-vpna] route-distinguisher 100:1

[PE1-vpn-instance-vpna] vpn-target 111:1

[PE1-vpn-instance-vpna] quit

[PE1] ip vpn-instance vpnb

[PE1-vpn-instance-vpnb] route-distinguisher 100:2

[PE1-vpn-instance-vpnb] vpn-target 222:2

[PE1-vpn-instance-vpnb] quit

[PE1] interface vlan-interface 1

[PE1-Vlan-interface1] ip binding vpn-instance vpna

[PE1-Vlan-interface1] ip address 10.1.1.2 24

[PE1-Vlan-interface1] quit

[PE1] interface vlan-interface 2

[PE1-Vlan-interface2] ip binding vpn-instance vpnb

[PE1-Vlan-interface2] ip address 10.2.1.2 24

[PE1-Vlan-interface2] quit

# Configure PE 2.

[PE2] ip vpn-instance vpna

[PE2-vpn-instance-vpna] route-distinguisher 200:1

[PE2-vpn-instance-vpna] vpn-target 111:1

[PE2-vpn-instance-vpna] quit

[PE2] ip vpn-instance vpnb

[PE2-vpn-instance-vpnb] route-distinguisher 200:2

[PE2-vpn-instance-vpnb] vpn-target 222:2

[PE2-vpn-instance-vpnb] quit

[PE2] interface vlan-interface 2

[PE2-Vlan-interface2] ip binding vpn-instance vpna

[PE2-Vlan-interface2] ip address 10.3.1.2 24

[PE2-Vlan-interface2] quit

[PE2] interface vlan-interface 3

[PE2-Vlan-interface3] ip binding vpn-instance vpnb

[PE2-Vlan-interface3] ip address 10.4.1.2 24

[PE2-Vlan-interface3] quit

# Configure IP addresses for the CEs as required in Figure 1-18. The detailed configuration steps are omitted.

After completing the above configurations, you can issue the display ip vpn-instance command on the PEs to view the configuration of the VPN instance. The PEs should be capable of pinging their respective CEs. The following takes PE 1 and CE 1 as an example:

[PE1] display ip vpn-instance

Total VPN-Instances configured : 2

VPN-Instance Name RD Create Time

vpna 100:1 2006/08/13 09:32:45

vpnb 100:2 2006/08/13 09:42:59

[PE1] ping -vpn-instance vpna 10.1.1.1

PING 10.1.1.1: 56 data bytes, press CTRL_C to break

Reply from 10.1.1.1: bytes=56 Sequence=1 ttl=255 time=56 ms

Reply from 10.1.1.1: bytes=56 Sequence=2 ttl=255 time=4 ms

Reply from 10.1.1.1: bytes=56 Sequence=3 ttl=255 time=4 ms

Reply from 10.1.1.1: bytes=56 Sequence=4 ttl=255 time=52 ms

Reply from 10.1.1.1: bytes=56 Sequence=5 ttl=255 time=3 ms

--- 10.1.1.1 ping statistics ---

5 packet(s) transmitted

5 packet(s) received

0.00% packet loss

round-trip min/avg/max = 3/23/56 ms

4) Establish EBGP peer relationship between PEs and CEs to allow VPN routes to be injected

# Configure CE 1.

[CE1] bgp 65410

[CE1-bgp] peer 10.1.1.2 as-number 100

[CE1-bgp] import-route direct

[CE1-bgp] quit

& Note:

The configurations for the other three CEs are similar to the above. The detailed configuration steps are omitted.

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp] ipv4-family vpn-instance vpna

[PE1-bgp-vpna] peer 10.1.1.1 as-number 65410

[PE1-bgp-vpna] import-route direct

[PE1-bgp-vpna] quit

[PE1-bgp] ipv4-family vpn-instance vpnb

[PE1-bgp-vpnb] peer 10.2.1.1 as-number 65420

[PE1-bgp-vpnb] import-route direct

[PE1-bgp-vpnb] quit

[PE1-bgp] quit

& Note:

The configurations for PE 2 are similar to those for PE 1. The detailed configuration steps are omitted.

After completing the above configuration, if you issue the display bgp vpnv4 vpn-instance peer command on the PEs, you should see that BGP peer relationship has been established between PE and CE, and has reached the state of Established. The following takes PE 1 and CE 1 as an example:

[PE1] display bgp vpnv4 vpn-instance vpna peer

BGP local router ID : 1.1.1.9

Local AS number : 100

Total number of peers : 1 Peers in established state : 1

Peer V AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State

10.1.1.1 4 65410 11 9 0 1 00:06:37 Established

5) Configure MP-IBGP peers between PEs

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp] peer 3.3.3.9 as-number 100

[PE1-bgp] peer 3.3.3.9 connect-interface loopback 0

[PE1-bgp] ipv4-family vpnv4

[PE1-bgp-af-vpnv4] peer 3.3.3.9 enable

[PE1-bgp-af-vpnv4] quit

# Configure PE 2.

[PE2] bgp 100

[PE2-bgp] peer 1.1.1.9 as-number 100

[PE2-bgp] peer 1.1.1.9 connect-interface loopback 0

[PE2-bgp] ipv4-family vpnv4

[PE2-bgp-af-vpnv4] peer 1.1.1.9 enable

[PE2-bgp-af-vpnv4] quit

After completing the above configuration, if you issue the display bgp peer command or the display bgp vpnv4 all peer command on the PEs, you should see that BGP peer relationship has been established between the PEs, and has reached the state of Established.

[PE1] display bgp peer

BGP local router ID : 1.1.1.9

Local AS number : 100

Total number of peers : 1 Peers in established state : 1

Peer V AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State

3.3.3.9 4 100 2 6 0 0 00:00:12 Established

6) Verify your configurations

Issuing the display ip routing-table vpn-instance command on the PEs, you should see the routes to the CEs. The following takes PE 1 as an example:

[PE1] display ip routing-table vpn-instance vpna

Routing Tables: vpna

Destinations : 3 Routes : 3

Destination/Mask Proto Pre Cost NextHop Interface

10.1.1.0/24 Direct 0 0 10.1.1.2 Vlan1

10.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0

10.3.1.0/24 BGP 255 0 3.3.3.9 NULL0

[PE1] display ip routing-table vpn-instance vpnb

Routing Tables: vpnb

Destinations : 3 Routes : 3

Destination/Mask Proto Pre Cost NextHop Interface

10.2.1.0/24 Direct 0 0 10.2.1.2 Vlan2

10.2.1.2/32 Direct 0 0 127.0.0.1 InLoop0

10.4.1.0/24 BGP 255 0 3.3.3.9 NULL0

CEs of the same VPN should be capable of pinging each other, whereas those of different VPNs should not. For example, CE 1 should be capable of pinging CE 3 (10.3.1.1), but should not be capable of pinging CE 4 (10.4.1.1):

[CE1] ping 10.3.1.1

PING 10.3.1.1: 56 data bytes, press CTRL_C to break

Reply from 10.3.1.1: bytes=56 Sequence=1 ttl=253 time=72 ms

Reply from 10.3.1.1: bytes=56 Sequence=2 ttl=253 time=34 ms

Reply from 10.3.1.1: bytes=56 Sequence=3 ttl=253 time=50 ms

Reply from 10.3.1.1: bytes=56 Sequence=4 ttl=253 time=50 ms

Reply from 10.3.1.1: bytes=56 Sequence=5 ttl=253 time=34 ms

--- 10.3.1.1 ping statistics ---

5 packet(s) transmitted

5 packet(s) received

0.00% packet loss

round-trip min/avg/max = 34/48/72 ms

[CE1] ping 10.4.1.1

PING 10.4.1.1: 56 data bytes, press CTRL_C to break

Request time out

--- 10.4.1.1 ping statistics ---

5 packet(s) transmitted

0 packet(s) received

100.00% packet loss

1.11.2 Example for Configuring Inter-Provider VPN Option A

I. Network requirements

l CE 1 and CE 2 belong to the same VPN. CE 1 accesses the network through PE 1 in AS 100 and CE 2 accesses the network through PE 2 in AS 200.

l Inter-provider MPLS L3VPN is implemented using option A. That is, the VRF-to-VRF method is used to manage VPN routes.

l The MPLS backbone in each AS runs OSPF.

II. Network diagram

Device	Interface	IP address	Device	Interface	IP address
CE 1	Vlan-int1	10.1.1.1/24	CE 2	Vlan-int1	10.2.1.1/24
PE 1	Loop0	1.1.1.9/32	PE 2	Loop0	4.4.4.9/32
	Vlan-int1	10.1.1.2/24		Vlan-int1	10.2.1.2/24
	Vlan-int2	172.1.1.2/24		Vlan-int2	162.1.1.2/24
ASBR-PE 1	Loop0	2.2.2.9/32	ASBR-PE 2	Loop0	3.3.3.9/32
	Vlan-int1	172.1.1.1/24		Vlan-int1	162.1.1.1/24
	Vlan-int2	192.1.1.1/24		Vlan-int2	192.1.1.2/24

Figure 1-19 Configure inter-provider VPN option A

III. Configuration procedure

1) Configure IGP on the MPLS backbone, implementing the connectivity in the backbone

This example uses OSPF. The detailed configuration steps are omitted.

& Note:

The 32-bit loopback interface address used as the LSR ID needs to be advertised by OSPF.

After you complete the above configurations, each ASBR PE and the PE in the same AS should be able to establish OSPF adjacencies. Issuing the display ospf peer command, you can see that the adjacencies reach the state of Full, and that PEs can learn the loopback addresses of each other.

Each ASBR PE and the PE in the same AS should be able to ping each other.

2) Configure MPLS basic capability and MPLS LDP on the MPLS backbone to establish LDP LSPs

# Configure MPLS basic capability on PE 1 and enable MPLS LDP on the interface connected to ASBR PE 1.

[PE1] mpls lsr-id 1.1.1.9

[PE1] mpls

[PE1-mpls] quit

[PE1] mpls ldp

[PE1-mpls-ldp] quit

[PE1] interface Vlan-interface 2

[PE1-Vlan-interface2] mpls

[PE1-Vlan-interface2] mpls ldp

[PE1-Vlan-interface2] quit

# Configure MPLS basic capability on ASBR PE 1 and enable MPLS LDP on the interface connected to PE 1.

[ASBR-PE1] mpls lsr-id 2.2.2.9

[ASBR-PE1] mpls

[ASBR-PE1-mpls] quit

[ASBR-PE1] mpls ldp

[ASBR-PE1-mpls-ldp] quit

[ASBR-PE1] interface Vlan-interface 1

[ASBR-PE1-Vlan-interface1] mpls

[ASBR-PE1-Vlan-interface1] mpls ldp

[ASBR-PE1-Vlan-interface1] quit

# Configure MPLS basic capability on ASBR PE 2 and enable MPLS LDP on the interface connected to PE 2.

[ASBR-PE2] mpls lsr-id 3.3.3.9

[ASBR-PE2] mpls

[ASBR-PE2-mpls] quit

[ASBR-PE2] mpls ldp

[ASBR-PE2-mpls-ldp] quit

[ASBR-PE2] interface Vlan-interface 1

[ASBR-PE2-Vlan-interface1] mpls

[ASBR-PE2-Vlan-interface1] mpls ldp

[ASBR-PE2-Vlan-interface1] quit

# Configure MPLS basic capability on PE 2 and enable MPLS LDP on the interface connected to ASBR PE 2.

[PE2] mpls lsr-id 4.4.4.9

[PE2] mpls

[PE2-mpls] quit

[PE2] mpls ldp

[PE2-mpls-ldp] quit

[PE2] interface vlna-interface 2

[PE2-Vlan-interface2] mpls

[PE2-Vlan-interface2] mpls ldp

[PE2-Vlan-interface2] quit

After you complete the above configurations, each PE and the ASBR PE in the same AS should be able to establish neighbor relationship. Issuing the display mpls ldp session command on the devices, you can see that the Session State field has a value of Operational in the output information.

3) Configure VPN instances on PEs to allow CEs to access

& Note:

The VPN targets for the VPN instances of the PEs must match those for the VPN instances of the ASBR-PEs in the same AS. It is not required for PEs in different ASs.

# Configure CE 1.

[CE1] interface Vlan-interface 1

[CE1-Vlan-interface1] ip address 10.1.1.1 24

[CE1-Vlan-interface1] quit

# Configure PE 1.

[PE1] ip vpn-instance vpna

[PE1-vpn-instance-vpna] route-distinguisher 100:1

[PE1-vpn-instance-vpna] vpn-target 100:1 both

[PE1-vpn-instance-vpna] quit

[PE1] interface Vlan-interface 1

[PE1-Vlan-interface1] ip binding vpn-instance vpna

[PE1-Vlan-interface1] ip address 10.1.1.2 24

[PE1-Vlan-interface1] quit

# Configure CE 2.

[CE2] interface Vlan-interface 1

[CE2-Vlan-interface1] ip address 10.2.1.1 24

[CE2-Vlan-interface1] quit

# Configure PE 2.

[PE2] ip vpn-instance vpna

[PE2-vpn-instance] route-distinguisher 200:2

[PE2-vpn-instance] vpn-target 100:1 both

[PE2-vpn-instance] quit

[PE2] interface Vlan-interface 1

[PE2-Vlan-interface1] ip binding vpn-instance vpna

[PE2-Vlan-interface1] ip address 10.2.1.2 24

[PE2-Vlan-interface1] quit

# Configure ASBR PE 1, creating a VPN instance and binding the instance to the interface connected with ASBR PE 2. Note that ASBR PE 1 considers ASBR PE 2 its CE.

[ASBR-PE1] ip vpn-instance vpna

[ASBR-PE1-vpn-instance-vpna] route-distinguisher 100:1

[ASBR-PE1-vpn-instance-vpna] vpn-target 100:1 both

[ASBR-PE1-vpn-instance-vpna] quit

[ASBR-PE1] interface Vlan-interface 2

[ASBR-PE1-Vlan-interface2] ip binding vpn-instance vpna

[ASBR-PE1-Vlan-interface2] ip address 192.1.1.1 24

[ASBR-PE1-Vlan-interface2] quit

# Configure ASBR PE 2, creating a VPN instance and binding the instance to the interface connected with ASBR PE 1. Note that ASBR PE 2 considers ASBR PE 1 its CE.

[ASBR-PE2] ip vpn-instance vpna

[ASBR-PE2-vpn-vpn-vpna] route-distinguisher 200:1

[ASBR-PE2-vpn-vpn-vpna] vpn-target 100:1 both

[ASBR-PE2-vpn-vpn-vpna] quit

[ASBR-PE2] interface Vlan-interface 2

[ASBR-PE2-Vlan-interface2] ip binding vpn-instance vpna

[ASBR-PE2-Vlan-interface2] ip address 192.1.1.2 24

[ASBR-PE2-Vlan-interface2] quit

After completing the above configurations, you should see the VPN instance configurations by issuing the display ip vpn-instance command.

The PEs should be able to ping the CEs and the ASBR PEs should be able to ping each other.

4) Establish EBGP peer relationship between PEs and CEs to allow VPN routes to be injected

# Configure CE 1.

[CE1] bgp 65001

[CE1-bgp] peer 10.1.1.2 as-number 100

[CE1-bgp] import-route direct

[CE1-bgp] import-route static

[CE1-bgp] quit

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp] ipv4-family vpn-instance vpna

[PE1-bgp-vpna] peer 10.1.1.1 as-number 65001

[PE1-bgp-vpna] import-route direct

[PE1-bgp-vpna] quit

[PE1-bgp] quit

# Configure CE 2.

[CE2] bgp 65002

[CE2-bgp] peer 10.2.1.2 as-number 200

[CE2-bgp] import-route direct

[CE2-bgp] import-route static

[CE2-bgp] quit

# Configure PE 2.

[PE2] bgp 200

[PE2-bgp] ipv4-family vpn-instance vpna

[PE2-bgp-vpna] peer 10.2.1.1 as-number 65002

[PE2-bgp-vpna] import-route direct

[PE2-bgp-vpna] quit

[PE2-bgp] quit

5) Establish IBGP peer relationship between each PE and the ASBR PE in the same AS and EBGP peer relationship between the ASBR PEs

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp] peer 2.2.2.9 as-number 100

[PE1-bgp] peer 2.2.2.9 connect-interface loopback 0

[PE1-bgp] ipv4-family vpnv4

[PE1-bgp-af-vpnv4] peer 2.2.2.9 enable

[PE1-bgp-af-vpnv4] peer 2.2.2.9 next-hop-local

[PE1-bgp-af-vpnv4] quit

[PE1-bgp] quit

# Configure ASBR PE 1.

[ASBR-PE1] bgp 100

[ASBR-PE1-bgp] ipv4-family vpn-instance vpna

[ASBR-PE1-bgp-vpna] peer 192.1.1.2 as-number 200

[ASBR-PE1-bgp-vpna] quit

[ASBR-PE1-bgp] peer 1.1.1.9 as-number 100

[ASBR-PE1-bgp] peer 1.1.1.9 connect-interface loopback 0

[ASBR-PE1-bgp] ipv4-family vpnv4

[ASBR-PE1-bgp-af-vpnv4] peer 1.1.1.9 enable

[ASBR-PE1-bgp-af-vpnv4] peer 1.1.1.9 next-hop-local

[ASBR-PE1-bgp-af-vpnv4] quit

[ASBR-PE1-bgp] quit

# Configure ASBR PE 2.

[ASBR-PE2] bgp 200

[ASBR-PE2-bgp] ipv4-family vpn-instance vpna

[ASBR-PE2-bgp-vpna] peer 192.1.1.1 as-number 100

[ASBR-PE2-bgp-vpna] quit

[ASBR-PE2-bgp] peer 4.4.4.9 as-number 200

[ASBR-PE2-bgp] peer 4.4.4.9 connect-interface loopback 0

[ASBR-PE2-bgp] ipv4-family vpnv4

[ASBR-PE2-bgp-af-vpnv4] peer 4.4.4.9 enable

[ASBR-PE2-bgp-af-vpnv4] peer 4.4.4.9 next-hop-local

[ASBR-PE2-bgp-af-vpnv4] quit

[ASBR-PE2-bgp] quit

# Configure PE 2.

[PE2] bgp 200

[PE2-bgp] peer 3.3.3.9 as-number 200

[PE2-bgp] peer 3.3.3.9 connect-interface loopback 0

[PE2-bgp] ipv4-family vpnv4

[PE2-bgp-af-vpnv4] peer 3.3.3.9 enable

[PE2-bgp-af-vpnv4] peer 3.3.3.9 next-hop-local

[PE2-bgp-af-vpnv4] quit

[PE2-bgp] quit

6) Verify your configurations

After you complete the above configurations, the CEs should be able to learn the interface routes from each other and ping each other.

1.11.3 Example for Configuring Inter-Provider VPN Option B

I. Network requirements

l Site 1 and Site 2 belong to the same VPN. CE 1 of Site 1 accesses the network through PE 1 in AS 100 and CE 2 of Site 2 accesses the network through PE 2 in AS 600.

l PEs in the same AS runs IS-IS between them.

l PE 1 and ASBR-PE 1 exchange labeled IPv4 routes by MP-IBGP.

l PE 2 and ASBR-PE 2 exchange labeled IPv4 routes by MP-IBGP.

l ASBR-PE 1 and ASBR-PE 2 exchange labeled IPv4 routes by MP-EBGP.

l ASBR-PEs do not perform VPN target filtering of received VPN-IPv4 routes.

II. Network diagram

Device	Interface	IP address	Device	Interface	IP address
PE 1	Loop1	2.2.2.9/32	PE 2	Loop1	5.5.5.9/32
	Vlan-int1	30.0.0.1/8		Vlan-int1	20.0.0.1/8
	Vlan-int2	1.1.1.2/8		Vlan-int2	9.1.1.2/8
ASBR-PE 1	Loop1	3.3.3.9/32	ASBR-PE 2	Loop1	4.4.4.9/32
	Vlan-int1	1.1.1.1/8		Vlan-int1	9.1.1.1/8
	Vlan-int2	11.0.0.2/8		Vlan-int2	11.0.0.1/8

Figure 1-20 Configure inter-provider VPN option B

III. Configuration procedure

1) Configure PE 1

<Sysname> system-view

[Sysname] sysname PE1

# Run IS-IS on PE 1.

[PE1] isis 1

[PE1-isis-1] network-entity 10.111.111.111.111.00

[PE1-isis-1] quit

# Configure LSR ID, enable MPLS and LDP.

[PE1] mpls lsr-id 2.2.2.9

[PE1] mpls

[PE1-mpls] quit

[PE1] mpls ldp

[PE1-mpls-ldp] quit

# Configure interface VLAN-interface 2, start IS-IS and enable MPLS and LDP on the interface.

[PE1] interface vlan-interface 2

[PE1-Vlan-interface2] ip address 1.1.1.2 255.0.0.0

[PE1-Vlan-interface2] isis enable 1

[PE1-Vlan-interface2] mpls

[PE1-Vlan-interface2] mpls ldp

[PE1-Vlan-interface2] quit

# Configure interface loopback1 and start IS-IS on it.

[PE1] interface loopback 1

[PE1-LoopBack1] ip address 2.2.2.9 32

[PE1-LoopBack1] isis enable 1

[PE1-LoopBack1] quit

# Create VPN instance vpn1 and configure the RD and VPN target attributes.

[PE1] ip vpn-instance vpn1

[PE1-vpn-instance-vpn1] route-distinguisher 11:11

[PE1-vpn-instance-vpn1] vpn-target 1:1 2:2 3:3 import-extcommunity

[PE1-vpn-instance-vpn1] vpn-target 3:3 export-extcommunity

[PE1-vpn-instance-vpn1] quit

# Bind the interface connected with CE 1 to the created VPN instance.

[PE1] interface vlan-interface 1

[PE1-Vlan-interface1] ip binding vpn-instance vpn1

[PE1-Vlan-interface1] ip address 30.0.0.1 8

[PE1-Vlan-interface1] quit

# Start BGP on PE 1.

[PE1] bgp 100

# Configure IBGP peer 3.3.3.9 as a VPNv4 peer.

[PE1-bgp] peer 3.3.3.9 as-number 100

[PE1-bgp] peer 3.3.3.9 connect-interface loopback 1

[PE1-bgp] ipv4-family vpnv4

[PE1-bgp-af-vpnv4] peer 3.3.3.9 enable

[PE1-bgp-af-vpnv4] quit

# Specify to inject direct routes to the VPN routing table of vpn1.

[PE1] bgp 100

[PE1-bgp] ipv4-family vpn-instance vpn1

[PE1-bgp-vpn1] import-route direct

[PE1-bgp-vpn1] quit

2) Configure ASBR-PE 1

<Sysname> system-view

[Sysname] sysname ASBR-PE1

# Start IS-IS on ASBR-PE 1.

[ASBR-PE1] isis 1

[ASBR-PE1-isis-1] network-entity 10.222.222.222.222.00

[ASBR-PE1-isis-1] quit

# Configure LSR ID, enable MPLS and LDP.

[ASBR-PE1] mpls lsr-id 3.3.3.9

[ASBR-PE1] mpls

[ASBR-PE1-mpls] quit

[ASBR-PE1] mpls ldp

[ASBR-PE1-mpls-ldp] quit

# Configure interface VLAN-interface 1, start IS-IS and enable MPLS and LDP on the interface.

[ASBR-PE1] interface vlan-interface 1

[ASBR-PE1-Vlan-interface1] ip address 1.1.1.1 255.0.0.0

[ASBR-PE1-Vlan-interface1] isis enable 1

[ASBR-PE1-Vlan-interface1] mpls

[ASBR-PE1-Vlan-interface1] mpls ldp

[ASBR-PE1-Vlan-interface1] quit

# Configure interface VLAN-interface 2 and enable MPLS on it.

[ASBR-PE1] interface vlan-interface 2

[ASBR-PE1-Vlan-interface2] ip address 11.0.0.2 255.0.0.0

[ASBR-PE1-Vlan-interface2] mpls

[ASBR-PE1-Vlan-interface2] quit

# Configure interface loopback1 and start IS-IS on it.

[ASBR-PE1] interface loopback 1

[ASBR-PE1-LoopBack1] ip address 3.3.3.9 32

[ASBR-PE1-LoopBack1] isis enable 1

[ASBR-PE1-LoopBack1] quit

# Start BGP on ASBR-PE 1.

[ASBR-PE1] bgp 100

[ASBR-PE1-bgp] peer 2.2.2.9 as-number 100

[ASBR-PE1-bgp] peer 2.2.2.9 connect-interface loopback 1

[ASBR-PE1-bgp] peer 11.0.0.1 as-number 600

[ASBR-PE1-bgp] peer 11.0.0.1 connect-interface vlan-interface 2

# Specify not to filter the received VPNv4 routes using the import target attribute.

[ASBR-PE1-bgp] ipv4-family vpnv4

[ASBR-PE1-bgp-af-vpnv4] undo policy vpn-target

# Configure both IBGP peer 2.2.2.0 and EBGP peer 11.0.0.1 as VPNv4 peers.

[ASBR-PE1-bgp-af-vpnv4] peer 11.0.0.1 enable

[ASBR-PE1-bgp-af-vpnv4] peer 2.2.2.9 enable

[ASBR-PE1-bgp-af-vpnv4] quit

3) Configure ASBR-PE 2

<Sysname> system-view

[Sysname] sysname ASBR-PE2

# Start IS-IS on ASBR-PE 2.

[ASBR-PE2] isis 1

[ASBR-PE2-isis-1] network-entity 10.222.222.222.222.00

[ASBR-PE2-isis-1] quit

# Configure LSR ID, enable MPLS and LDP.

[ASBR-PE2] mpls lsr-id 4.4.4.9

[ASBR-PE2] mpls

[ASBR-PE2-mpls] quit

[ASBR-PE2] mpls ldp

[ASBR-PE2-mpls-ldp] quit

# Configure interface VLAN-interface 1, start IS-IS and enable MPLS and LDP on the interface.

[ASBR-PE2] interface vlan-interface 1

[ASBR-PE2-Vlan-interface1] ip address 9.1.1.1 255.0.0.0

[ASBR-PE2-Vlan-interface1] isis enable 1

[ASBR-PE2-Vlan-interface1] mpls

[ASBR-PE2-Vlan-interface1] mpls ldp

[ASBR-PE2-Vlan-interface1] quit

# Configure interface VLAN-interface 2 and enable MPLS on it.

[ASBR-PE2] interface vlan-interface 2

[ASBR-PE2-Vlan-interface2] ip address 11.0.0.1 255.0.0.0

[ASBR-PE2-Vlan-interface2] mpls

[ASBR-PE2-Vlan-interface2] quit

# Configure interface loopback1 and start IS-IS on it.

[ASBR-PE2] interface loopback 1

[ASBR-PE2-LoopBack1] ip address 4.4.4.9 32

[ASBR-PE2-LoopBack1] isis enable 1

[ASBR-PE2-LoopBack1] quit

# Start BGP on ASBR-PE 2.

[ASBR-PE2] bgp 600

[ASBR-PE2-bgp] peer 11.0.0.2 as-number 100

[ASBR-PE2-bgp] peer 11.0.0.2 connect-interface vlan-interface 2

[ASBR-PE2-bgp] peer 5.5.5.9 as-number 600

[ASBR-PE2-bgp] peer 5.5.5.9 connect-interface loopback 1

# Specify not to filter the received VPNv4 routes using the import target attribute.

[ASBR-PE2-bgp] ipv4-family vpnv4

[ASBR-PE2-bgp-af-vpnv4] undo policy vpn-target

# Configure both IBGP peer 5.5.5.9 and EBGP peer 11.0.0.2 as VPNv4 peers.

[ASBR-PE2-bgp-af-vpnv4] peer 11.0.0.2 enable

[ASBR-PE2-bgp-af-vpnv4] peer 5.5.5.9 enable

[ASBR-PE2-bgp-af-vpnv4] quit

[ASBR-PE2-bgp] quit

4) Configure PE 2

<Sysname> system-view

[Sysname] sysname PE2

# Start IS-IS on PE 2.

[PE2] isis 1

[PE2-isis-1] network-entity 10.111.111.111.111.00

[PE2-isis-1] quit

# Configure LSR ID, enable MPLS and LDP.

[PE2] mpls lsr-id 5.5.5.9

[PE2] mpls

[PE2-mpls] quit

[PE2] mpls ldp

[PE2-mpls-ldp] quit

# Configure interface VLAN-interface 2, start IS-IS and enable MPLS and LDP on the interface.

[PE2] interface vlan-interface 2

[PE2-Vlan-interface2] ip address 9.1.1.2 255.0.0.0

[PE2-Vlan-interface2] isis enable 1

[PE2-Vlan-interface2] mpls

[PE2-Vlan-interface2] mpls ldp

[PE2-Vlan-interface2] quit

# Configure interface loopback1 and start IS-IS on it.

[PE2] interface loopback 1

[PE2-LoopBack1] ip address 5.5.5.9 32

[PE2-LoopBack1] isis enable 1

[PE2-LoopBack1] quit

# Create VPN instance vpn1 and configure the RD and VPN target attributes.

[PE2] ip vpn-instance vpn1

[PE2-vpn-instance-vpn1] route-distinguisher 12:12

[PE2-vpn-instance-vpn1] vpn-target 1:1 2:2 3:3 import-extcommunity

[PE2-vpn-instance-vpn1] vpn-target 3:3 export-extcommunity

[PE2-vpn-instance-vpn1] quit

# Bind the interface connected with CE 2 to the created VPN instance.

[PE2] interface vlan-interface 1

[PE2-Vlan-interface1] ip binding vpn-instance vpn1

[PE2-Vlan-interface1] ip address 20.0.0.1 8

[PE2-Vlan-interface1] quit

# Start BGP on PE 2.

[PE2] bgp 600

# Configure IBGP peer 4.4.4.9 as a VPNv4 peer.

[PE2-bgp] peer 4.4.4.9 as-number 600

[PE2-bgp] peer 4.4.4.9 connect-interface loopback 1

[PE2-bgp] ipv4-family vpnv4

[PE2-bgp-af-vpnv4] peer 4.4.4.9 enable

[PE2-bgp-af-vpnv4] quit

# Specify to inject direct routes to the VPN routing table of vpn1.

[PE2] bgp 600

[PE2-bgp] ipv4-family vpn-instance vpn1

[PE2-bgp-vpn1] import-route direct

[PE2-bgp-vpn1] quit

[PE2-bgp] quit

5) Verify your configurations

After you complete the above configurations, PE 1 and PE 2 should be able to ping each other:

[PE2] ping –vpn-instance vpn1 30.0.0.1

[PE1] ping –vpn-instance vpn1 20.0.0.1

1.11.4 Example for Configuring Inter-Provider VPN Option C

I. Network requirements

l Site 1 and Site 2 belong to the same VPN. Site 1 accesses the network through PE 1 in AS 100 and Site 2 accesses the network through PE 2 in AS 600.

l PEs in the same AS runs IS-IS between them.

l PE 1 and ASBR-PE 1 exchange labeled IPv4 routes by MP-IBGP.

l PE 2 and ASBR-PE 2 exchange labeled IPv4 routes by MP-IBGP.

l PE 1 and PE 2 are MP-EBGP peers.

l ASBR-PE 1 and ASBR-PE 2 use their respective routing policies and label the routes received from each other.

l ASBR-PE 1 and ASBR-PE 2 use MP-EBGP to exchange labeled IPv4 routes.

II. Network diagram

Device	Interface	IP address	Device	Interface	IP address
PE 1	Loop1	2.2.2.9/32	PE 2	Loop1	5.5.5.9/32
	Loop6	30.0.0.1/32		Loop6	20.0.0.1/32
	Vlan-int1	1.1.1.2/8		Vlan-int1	9.1.1.2/8
ASBR-PE 1	Loop1	3.3.3.9/32	ASBR-PE 2	Loop1	4.4.4.9/32
	Vlan-int1	1.1.1.1/8		Vlan-int1	9.1.1.1/8
	Vlan-int2	11.0.0.2/8		Vlan-int2	11.0.0.1/8

Figure 1-21 Configure inter-provider VPN option C

III. Configuration procedure

1) Configure PE 1

<Sysname> system-view

[Sysname] sysname PE1

# Run IS-IS on PE 1.

[PE1] isis 1

[PE1-isis-1] network-entity 10.111.111.111.111.00

[PE1-isis-1] quit

# Configure LSR ID, enable MPLS and LDP.

[PE1] mpls lsr-id 2.2.2.9

[PE1] mpls

[PE1-mpls] quit

[PE1] mpls ldp

[PE1-mpls-ldp] quit

# Configure interface VLAN-interface 1, start IS-IS and enable MPLS and LDP on the interface.

[PE1] interface vlan-interface 1

[PE1-Vlan-interface1] ip address 1.1.1.2 255.0.0.0

[PE1-Vlan-interface1] isis enable 1

[PE1-Vlan-interface1] mpls

[PE1-Vlan-interface1] mpls ldp

[PE1-Vlan-interface1] quit

# Configure interface loopback1 and start IS-IS on it.

[PE1] interface loopback 1

[PE1-LoopBack1] ip address 2.2.2.9 32

[PE1-LoopBack1] isis enable 1

[PE1-LoopBack1] quit

# Create VPN instance vpn1 and configure the RD and VPN target attributes.

[PE1] ip vpn-instance vpn1

[PE1-vpn-instance-vpn1] route-distinguisher 11:11

[PE1-vpn-instance-vpn1] vpn-target 1:1 2:2 3:3 import-extcommunity

[PE1-vpn-instance-vpn1] vpn-target 3:3 export-extcommunity

[PE1-vpn-instance-vpn1] quit

# Configure interface loopback6 and bind the interface to VPN instance vpn1.

[PE1] interface loopback 6

[PE1-LoopBack6] ip binding vpn-instance vpn1

[PE1-LoopBack6] ip address 30.0.0.1 32

[PE1-LoopBack6] quit

# Start BGP on PE 1.

[PE1] bgp 100

# Configure the capability to advertise labeled routes to IBGP peer 3.3.3.9 and to receive labeled routes from the peer.

[PE1-bgp] peer 3.3.3.9 as-number 100

[PE1-bgp] peer 3.3.3.9 connect-interface loopback 1

[PE1-bgp] peer 3.3.3.9 label-route-capability

# Configure the maximum hop count from PE 1 to EBGP peer 5.5.5.9 as 10.

[PE1-bgp] peer 5.5.5.9 as-number 600

[PE1-bgp] peer 5.5.5.9 connect-interface loopback 1

[PE1-bgp] peer 5.5.5.9 ebgp-max-hop 10

# Configure peer 5.5.5.9 as a VPNv4 peer.

[PE1-bgp] ipv4-family vpnv4

[PE1-bgp-af-vpnv4] peer 5.5.5.9 enable

[PE1-bgp-af-vpnv4] quit

# Specify to inject direct routes to the routing table of vpn1.

[PE1-bgp] ipv4-family vpn-instance vpn1

[PE1-bgp-vpn1] import-route direct

[PE1-bgp-vpn1] quit

2) Configure ASBR-PE 1

<Sysname> system-view

[Sysname] sysname ASBR-PE1

# Start IS-IS on ASBR-PE 1.

<ASBR-PE1> system-view

[ASBR-PE1] isis 1

[ASBR-PE1-isis-1] network-entity 10.222.222.222.222.00

[ASBR-PE1-isis-1] quit

# Configure LSR ID, enable MPLS and LDP.

[ASBR-PE1] mpls lsr-id 3.3.3.9

[ASBR-PE1] mpls

[ASBR-PE1-mpls] quit

[ASBR-PE1] mpls ldp

[ASBR-PE1-mpls-ldp] quit

# Configure interface VLAN-interface 1, start IS-IS and enable MPLS and LDP on the interface.

[ASBR-PE1] interface vlan-interface 1

[ASBR-PE1-Vlan-interface1] ip address 1.1.1.1 255.0.0.0

[ASBR-PE1-Vlan-interface1] isis enable 1

[ASBR-PE1-Vlan-interface1] mpls

[ASBR-PE1-Vlan-interface1] mpls ldp

[ASBR-PE1-Vlan-interface1] quit

# Configure interface VLAN-interface 2 and enable MPLS on it.

[ASBR-PE1] interface vlan-interface 2

[ASBR-PE1-Vlan-interface2] ip address 11.0.0.2 255.0.0.0

[ASBR-PE1-Vlan-interface2] mpls

[ASBR-PE1-Vlan-interface2] quit

# Configure interface loopback1 and start IS-IS on it.

[ASBR-PE1] interface loopback 1

[ASBR-PE1-LoopBack1] ip address 3.3.3.9 32

[ASBR-PE1-LoopBack1] isis enable 1

[ASBR-PE1-LoopBack1] quit

# Create routing policies.

[ASBR-PE1] route-policy policy1 permit node 1

New Sequence of this List

[ASBR-PE1-route-policy] apply mpls-label

[ASBR-PE1-route-policy] quit

[ASBR-PE1] route-policy policy2 permit node 1

New Sequence of this List

[ASBR-PE1-route-policy] if-match mpls-label

[ASBR-PE1-route-policy] apply mpls-label

[ASBR-PE1-route-policy] quit

# Start BGP on ASBR-PE 1 and specify to inject routes of IS-IS process 1.

[ASBR-PE1] bgp 100

[ASBR-PE1-bgp] import-route isis 1

# Configure the capability to advertise labeled routes to IBGP peer 2.2.2.9 and to receive labeled routes from the peer.

[ASBR-PE1-bgp] peer 2.2.2.9 as-number 100

[ASBR-PE1-bgp] peer 2.2.2.9 connect-interface loopback 1

[ASBR-PE1-bgp] peer 2.2.2.9 label-route-capability

# Specify to use routing policy policy2 to filter routes advertised from IBGP peer 2.2.2.9.

[ASBR-PE1-bgp] peer 2.2.2.9 route-policy policy2 export

# Specify to use routing policy policy1 to filter routes advertised from EBGP peer 11.0.0.1.

[ASBR-PE1-bgp] peer 11.0.0.1 as-number 600

[ASBR-PE1-bgp] peer 11.0.0.1 route-policy policy1 export

# Configure the capability to advertise labeled routes to EBGP peer 11.0.0.1 and to receive labeled routes from the peer.

[ASBR-PE1-bgp] peer 11.0.0.1 label-route-capability

3) Configure ASBR-PE 2

<Sysname> system-view

[Sysname] sysname ASBR-PE2

# Start IS-IS on ASBR-PE 2.

[ASBR-PE2] isis 1

[ASBR-PE2-isis-1] network-entity 10.222.222.222.222.00

[ASBR-PE2-isis-1] quit

# Configure LSR ID, enable MPLS and LDP.

[ASBR-PE2] mpls lsr-id 4.4.4.9

[ASBR-PE2] mpls

[ASBR-PE2-mpls] quit

[ASBR-PE2] mpls ldp

[ASBR-PE2-mpls-ldp] quit

# Configure interface VLAN-interface 1, start IS-IS and enable MPLS and LDP on the interface.

[ASBR-PE2] interface vlan-interface 1

[ASBR-PE2-Vlan-interface1] ip address 9.1.1.1 255.0.0.0

[ASBR-PE2-Vlan-interface1] isis enable 1

[ASBR-PE2-Vlan-interface1] mpls

[ASBR-PE2-Vlan-interface1] mpls ldp

[ASBR-PE2-Vlan-interface1] quit

# Configure interface loopback1 and start IS-IS on it.

[ASBR-PE2] interface loopback 1

[ASBR-PE2-LoopBack1] ip address 4.4.4.9 32

[ASBR-PE2-LoopBack1] isis enable 1

[ASBR-PE2-LoopBack1] quit

# Configure interface VLAN-interface 2 and enable MPLS on it.

[ASBR-PE2] interface vlan-interface 2

[ASBR-PE2-Vlan-interface2] ip address 11.0.0.1 255.0.0.0

[ASBR-PE2-Vlan-interface2] mpls

[ASBR-PE2-Vlan-interface2] quit

# Create routing policies.

[ASBR-PE2] route-policy policy1 permit node 1

New Sequence of this List

[ASBR-PE2-route-policy] apply mpls-label

[ASBR-PE2-route-policy] quit

[ASBR-PE2] route-policy policy2 permit node 1

New Sequence of this List

[ASBR-PE2-route-policy] if-match mpls-label

[ASBR-PE2-route-policy] apply mpls-label

[ASBR-PE2-route-policy] quit

# Start BGP on ASBR-PE 2 and specify to inject routes of IS-IS process 1.

[ASBR-PE2] bgp 600

[ASBR-PE2-bgp] import-route isis 1

# Configure the capability to advertise labeled routes to IBGP peer 5.5.5.9 and to receive labeled routes from the peer.

[ASBR-PE2-bgp] peer 5.5.5.9 as-number 600

[ASBR-PE2-bgp] peer 5.5.5.9 connect-interface loopback 1

[ASBR-PE2-bgp] peer 5.5.5.9 label-route-capability

# Specify to use routing policy policy2 to filter routes advertised from IBGP peer 5.5.5.9.

[ASBR-PE2-bgp] peer 5.5.5.9 route-policy policy2 export

# Specify to use routing policy policy1 to filter routes advertised from EBGP peer 11.0.0.2.

[ASBR-PE2-bgp] peer 11.0.0.2 as-number 100

[ASBR-PE2-bgp] peer 11.0.0.2 route-policy policy1 export

# Configure the capability to advertise labeled routes to EBGP peer 11.0.0.2 and to receive labeled routes from the peer.

[ASBR-PE2-bgp] peer 11.0.0.2 label-route-capability

[ASBR-PE2-bgp] quit

4) Configure PE 2

<Sysname> system-view

[Sysname] sysname PE2

# Start IS-IS on PE 2.

[PE2] isis 1

[PE2-isis-1] network-entity 10.111.111.111.111.00

[PE2-isis-1] quit

# Configure LSR ID, enable MPLS and LDP.

[PE2] mpls lsr-id 5.5.5.9

[PE2] mpls

[PE2-mpls] quit

[PE2] mpls ldp

[PE2-mpls-ldp] quit

# Configure interface VLAN-interface 1, start IS-IS and enable MPLS and LDP on the interface.

[PE2] interface vlan-interface 1

[PE2-Vlan-interface1] ip address 9.1.1.2 255.0.0.0

[PE2-Vlan-interface1] isis enable 1

[PE2-Vlan-interface1] mpls

[PE2-Vlan-interface1] mpls ldp

[PE2-Vlan-interface1] quit

# Configure interface loopback1 and start IS-IS on it.

[PE2] interface loopback 1

[PE2-LoopBack1] ip address 5.5.5.9 32

[PE2-LoopBack1] isis enable 1

[PE2-LoopBack1] quit

# Create VPN instance vpn1 and configure the RD and VPN target attributes.

[PE2] ip vpn-instance vpn1

[PE2-vpn-instance-vpn1] route-distinguisher 11:11

[PE2-vpn-instance-vpn1] vpn-target 1:1 2:2 3:3 import-extcommunity

[PE2-vpn-instance-vpn1] vpn-target 3:3 export-extcommunity

[PE2-vpn-instance-vpn1] quit

# Configure interface loopback6 and bind the interface to VPN instance vpn1.

[PE2] interface loopback 6

[PE2-LoopBack6] ip binding vpn-instance vpn1

[PE2-LoopBack6] ip address 20.0.0.1 32

[PE2-LoopBack6] quit

# Start BGP on PE 2.

[PE2] bgp 600

# Configure the capability to advertise labeled routes to IBGP peer 4.4.4.9 and to receive labeled routes from the peer.

[PE2-bgp] peer 4.4.4.9 as-number 600

[PE2-bgp] peer 4.4.4.9 connect-interface loopback 1

[PE2-bgp] peer 4.4.4.9 label-route-capability

# Configure the maximum hop count from PE 2 to EBGP peer 2.2.2.9 as 10.

[PE2-bgp] peer 2.2.2.9 as-number 100

[PE2-bgp] peer 2.2.2.9 connect-interface loopback 1

[PE2-bgp] peer 2.2.2.9 ebgp-max-hop 10

# Configure peer 2.2.2.9 as a VPNv4 peer.

[PE2-bgp] ipv4-family vpnv4

[PE2-bgp-af-vpnv4] peer 2.2.2.9 enable

[PE2-bgp-af-vpnv4] quit

# Specify to inject direct routes to the routing table of vpn1.

[PE2-bgp] ipv4-family vpn-instance vpn1

[PE2-bgp-vpn1] import-route direct

[PE2-bgp-vpn1] quit

After you complete the above configurations, PE 1 and PE 2 should be able to ping each other:

[PE2] ping –vpn-instance vpn1 30.0.0.1

[PE1] ping –vpn-instance vpn1 20.0.0.1

1.11.5 Example for Configuring Carrier’s Carrier

I. Network requirements

The Level 2 carrier provides MPLS L3VPN services to customers.

As shown in Figure 1-22,

l PE 1 and PE 2 are PEs of the Level 1 carrier backbone.

l CE 1 and CE 2 are devices of the Level 2 carrier and work as CE to access the Level 1 carrier backbone.

l PE 3 and PE 4 are devices of the Level 2 carrier and work as PE to provide access service for the customers of the Level 2 carrier.

l CE 3 and CE 4 are customers of the Level 2 carrier.

The key of the carrier’s carrier configuration lies in the exchange process of two kinds of routes:

l The exchange of the internal Level 2 carrier VPN routes on the Level 1 carrier backbone. In this process, the Level 2 carrier accesses the Level 1 carrier backbone as CE.

The exchange of customer VPN routes of the Level 2 carrier between PEs of the Level 2 carrier. In this process, MP-IBGP peer relationship must be established between the PEs of the Level 2 carrier (that is, between PE 3 and PE 4).

& Note:

On an S9500 Series routing switch, an LPU with a suffix of C does not support the carrier’s carrier feature.

II. Network diagram

Device	Interface	IP address	Device	Interface	IP address
CE 3	Vlan-int1	100.1.1.1/24	CE 4	Vlan-int1	120.1.1.1/24
PE 3	Loop1	1.1.1.9/32	PE 4	Loop1	6.6.6.9/32
	Vlan-int1	100.1.1.2/24		Vlan-int1	120.1.1.2/24
	Vlan-int2	10.1.1.1/24		Vlan-int2	20.1.1.2/24
CE 1	Loop1	2.2.2.9/32	CE 2	Loop1	5.5.5.9/32
	Vlan-int2	10.1.1.2/24		Vlan-int1	21.1.1.2/24
	Vlan-int1	11.1.1.1/24		Vlan-int2	20.1.1.1/24
PE 1	Loop1	3.3.3.9/32	PE 2	Loop1	4.4.4.9/32
	Vlan-int1	11.1.1.2/24		Vlan-int2	30.1.1.2/24
	Vlan-int2	30.1.1.1/24		Vlan-int1	21.1.1.1/24

Figure 1-22 Configure carrier’s carrier

III. Configuration procedure

1) Configure MPLS L3VPN on the Level 1 carrier backbone: start IS-IS as the IGP, enable LDP between PE 1 and PE 2, and establish MP-IBGP peer relationship between the PEs

# Configure PE 1.

<Sysname> system-view

[Sysname] sysname PE1

[PE1] interface loopback 1

[PE1-LoopBack1] ip address 3.3.3.9 32

[PE1-LoopBack1] quit

[PE1] mpls lsr-id 3.3.3.9

[PE1] mpls

[PE1-mpls] quit

[PE1] mpls ldp

[PE1-mpls-ldp] quit

[PE1] isis 1

[PE1-isis-1] network-entity 10.0000.0000.0000.0004.00

[PE1-isis-1] quit

[PE1] interface loopback 1

[PE1-LoopBack1] isis enable 1

[PE1-LoopBack1] quit

[PE1] interface vlan-interface 2

[PE1-Vlan-interface2] ip address 30.1.1.1 24

[PE1-Vlan-interface2] isis enable 1

[PE1-Vlan-interface2] mpls

[PE1-Vlan-interface2] mpls ldp

[PE1-Vlan-interface2] mpls ldp transport-address interface

[PE1-Vlan-interface2] quit

[PE1] bgp 100

[PE1-bgp] peer 4.4.4.9 as-number 100

[PE1-bgp] peer 4.4.4.9 connect-interface loopback 1

[PE1-bgp] ipv4-family vpnv4

[PE1-bgp-af-vpnv4] peer 4.4.4.9 enable

[PE1-bgp-af-vpnv4] quit

[PE1-bgp] quit

& Note:

The configurations for PE 2 are similar to those for PE 1. The detailed configuration steps are omitted.

After completing the above configurations, you should see that the LDP session has been established successfully by issuing the display mpls ldp session command on PE 1 or PE 2. Issuing the display bgp peer command, you should see that the BGP peer relationship has been established and has reached the state of Established. Issuing the display isis peer command, you should see that the IS-IS neighbor relationship has been set up. Take PE 1 as an example:

[PE1] display mpls ldp session

LDP Session(s) in Public Network

Total number of sessions: 1

----------------------------------------------------------------

Peer-ID Status LAM SsnRole FT MD5 KA-Sent/Rcv

----------------------------------------------------------------

4.4.4.9:0 Operational DU Active Off Off 378/378

----------------------------------------------------------------

LAM : Label Advertisement Mode FT : Fault Tolerance

[PE1] display bgp peer

BGP local router ID : 3.3.3.9

Local AS number : 100

Total number of peers : 1 Peers in established state : 1

Peer V AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State

4.4.4.9 4 100 162 145 0 0 02:12:47 Established

[PE1] display isis peer

Peer information for ISIS(1)

----------------------------

System Id: 0000.0000.0005

Interface: Vlan-interface44 Circuit Id: 0000.0000.0004.02

State: Up HoldTime: 29s Type: L1(L1L2) PRI: 64

System Id: 0000.0000.0005

Interface: Vlan-interface44 Circuit Id: 0000.0000.0004.02

State: Up HoldTime: 30s Type: L2(L1L2) PRI: 64

2) Configure the Level 2 carrier network: start IS-IS as the IGP and enable LDP between PE 3 and CE 1, and between PE 4 and CE 2 respectively

# Configure PE 3.

<Sysname> system-view

[Sysname] sysname PE3

[PE3] interface loopback 1

[PE3-LoopBack1] ip address 1.1.1.9 32

[PE3-LoopBack1] quit

[PE3] mpls lsr-id 1.1.1.9

[PE3] mpls

[PE3-mpls] quit

[PE3] mpls ldp

[PE3-mpls-ldp] quit

[PE3] isis 2

[PE3-isis-2] network-entity 10.0000.0000.0000.0001.00

[PE3-isis-2] quit

[PE3] interface loopback 1

[PE3-LoopBack1] isis enable 2

[PE3-LoopBack1] quit

[PE3] interface vlan-interface 2

[PE3-Vlan-interface2] ip address 10.1.1.1 24

[PE3-Vlan-interface2] isis enable 2

[PE3-Vlan-interface2] mpls

[PE3-Vlan-interface2] mpls ldp

[PE3-Vlan-interface2] mpls ldp transport-address interface

[PE3-Vlan-interface2] quit

# Configure CE 1.

<Sysname> system-view

[Sysname] sysname CE1

[CE1] interface loopback 1

[CE1-LoopBack1] ip address 2.2.2.9 32

[CE1-LoopBack1] quit

[CE1] mpls lsr-id 2.2.2.9

[CE1] mpls

[CE1-mpls] quit

[CE1] mpls ldp

[CE1-mpls-ldp] quit

[CE1] isis 2

[CE1-isis-2] network-entity 10.0000.0000.0000.0002.00

[CE1-isis-2] quit

[CE1] interface loopback 1

[CE1-LoopBack1] isis enable 2

[CE1-LoopBack1] quit

[CE1] interface vlan-interface 2

[CE1-Vlan-interface2] ip address 10.1.1.2 24

[CE1-Vlan-interface2] isis enable 2

[CE1-Vlan-interface2] mpls

[CE1-Vlan-interface2] mpls ldp

[CE1-Vlan-interface2] mpls ldp transport-address interface

[CE1-Vlan-interface2] quit

After you complete the above configurations, PE 3 and CE 1 should be able to establish the LDP session and IS-IS neighbor relationship between them.

& Note:

The configurations for PE 4 and CE 2 are similar to those for PE 3 and CE 1. The detailed configuration steps are omitted.

3) Perform configuration to allow CEs of the Level 2 carrier to access PEs of the Level 1 carrier

# Configure PE 1.

[PE1] ip vpn-instance vpn1

[PE1-vpn-instance-vpn1] route-distinguisher 200:1

[PE1-vpn-instance-vpn1] vpn-target 1:1

[PE1-vpn-instance-vpn1] quit

[PE1] mpls ldp vpn-instance vpn1

[PE1-mpls-ldp-vpn-instance-vpn1] quit

[PE1] isis 2 vpn-instance vpn1

[PE1-isis-2] network-entity 10.0000.0000.0000.0003.00

[PE1-isis-2] import-route bgp

[PE1-isis-2] quit

[PE1] interface vlan-interface 1

[PE1-Vlan-interface1] ip binding vpn-instance vpn1

[PE1-Vlan-interface1] ip address 11.1.1.2 24

[PE1-Vlan-interface1] isis enable 2

[PE1-Vlan-interface1] mpls

[PE1-Vlan-interface1] mpls ldp

[PE1-Vlan-interface1] mpls ldp transport-address interface

# Configure CE 1.

[CE1] interface vlan-interface 1

[CE1-Vlan-interface1] ip address 11.1.1.1 24

[CE1-Vlan-interface1] isis enable 2

[CE1-Vlan-interface1] mpls

[CE1-Vlan-interface1] mpls ldp

[CE1-Vlan-interface1] mpls ldp transport-address interface

[CE1-Vlan-interface1] quit

After you complete the above configurations, PE 1 and CE 1 should be able to establish the LDP session and IS-IS neighbor relationship between them.

& Note:

The configurations for PE 2 and CE 2 are similar to those for PE 1 and CE 1. The detailed configuration steps are omitted.

4) Perform configuration to allow the CEs of the Level 2 carrier to access the PEs

# Configure CE 3.

<Sysname> system-view

[Sysname] sysname CE3

[CE3] interface vlan-interface 1

[CE3-Vlan-interface1] ip address 100.1.1.1 24

[CE3-Vlan-interface1] quit

[CE3] bgp 65410

[CE3-bgp] peer 100.1.1.2 as-number 100

[CE3-bgp] import-route direct

[CE3-bgp] quit

# Configure PE 3.

[PE3] ip vpn-instance vpn1

[PE3-vpn-instance-vpn1] route-distinguisher 100:1

[PE3-vpn-instance-vpn1] vpn-target 1:1

[PE3-vpn-instance-vpn1] quit

[PE3] interface vlan-interface 1

[PE3-Vlan-interface1] ip binding vpn-instance vpn1

[PE3-Vlan-interface1] ip address 100.1.1.2 24

[PE3-Vlan-interface1] quit

[PE3] bgp 100

[PE3-bgp] ipv4-family vpn-instance vpn1

[PE3-bgp-vpn1] peer 100.1.1.1 as-number 65410

[PE3-bgp-vpn1] import-route direct

[PE3-bgp-vpn1] quit

[PE3-bgp] quit

& Note:

The configurations for PE 4 and CE 4 are similar to those for PE 3 and CE 3. The detailed configuration steps are omitted.

5) Configure MP-IBGP peer relationship between PEs of the Level 2 carrier to exchange the VPN routes of the Level 2 carrier customers

# Configure PE 3.

[PE3] bgp 100

[PE3-bgp] peer 6.6.6.9 as-number 100

[PE3-bgp] peer 6.6.6.9 connect-interface loopback 1

[PE3-bgp] ipv4-family vpnv4

[PE3-bgp-af-vpnv4] peer 6.6.6.9 enable

[PE3-bgp-af-vpnv4] quit

[PE3-bgp] quit

& Note:

The configurations for PE 4 are similar to those for PE 3. The detailed configuration steps are omitted.

6) Verify your configurations

After completing all the above configurations, you can issue the display ip routing-table command on PE 1 and PE 2. You should see that only routes of the Level 1 carrier network are present in the public network routing table of PE 1 and PE 2. Takes PE 1 as an example:

[PE1] display ip routing-table

Routing Tables: Public

Destinations : 7 Routes : 7

Destination/Mask Proto Pre Cost NextHop Interface

3.3.3.9/32 Direct 0 0 127.0.0.1 InLoop0

4.4.4.9/32 ISIS 15 10 30.1.1.2 Vlan2

30.1.1.0/24 Direct 0 0 30.1.1.1 Vlan2

30.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

30.1.1.2/32 Direct 0 0 30.1.1.2 Vlan2

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

Issuing the display ip routing-table vpn-instance command on PE 1 and PE 2, you should see that the internal routes of the Level 2 carrier network are present in the VPN routing tables, but the VPN routes that the Level 2 carrier maintains are not. Takes PE 1 as an example:

[PE1] display ip routing-table vpn-instance vpn1

Routing Tables: vpn1

Destinations : 11 Routes : 11

Destination/Mask Proto Pre Cost NextHop Interface

1.1.1.9/32 ISIS 15 20 11.1.1.1 Vlan1

2.2.2.9/32 ISIS 15 10 11.1.1.1 Vlan1

5.5.5.9/32 BGP 255 0 4.4.4.9 NULL0

6.6.6.9/32 BGP 255 0 4.4.4.9 NULL0

10.1.1.0/24 ISIS 15 20 11.1.1.1 Vlan1

11.1.1.0/24 Direct 0 0 11.1.1.1 Vlan1

11.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

11.1.1.2/32 Direct 0 0 11.1.1.2 Vlan1

20.1.1.0/24 BGP 255 0 4.4.4.9 NULL0

21.1.1.0/24 BGP 255 0 4.4.4.9 NULL0

21.1.1.2/32 BGP 255 0 4.4.4.9 NULL0

Issuing the display ip routing-table command on CE 1 and CE 2, you should see that the internal routes of the Level 2 carrier network are present in the public network routing tables, but the VPN routes that the Level 2 carrier maintains are not. Takes CE 1 as an example:

[CE1] display ip routing-table

Routing Tables: Public

Destinations : 16 Routes : 16

Destination/Mask Proto Pre Cost NextHop Interface

1.1.1.9/32 ISIS 15 10 10.1.1.2 Vlan2

2.2.2.9/32 Direct 0 0 127.0.0.1 InLoop0

5.5.5.9/32 ISIS 15 74 11.1.1.2 Vlan1

6.6.6.9/32 ISIS 15 74 11.1.1.2 Vlan1

10.1.1.0/24 Direct 0 0 10.1.1.2 Vlan2

10.1.1.1/32 Direct 0 0 10.1.1.1 Vlan2

10.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0

11.1.1.0/24 Direct 0 0 11.1.1.1 Vlan1

11.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

11.1.1.2/32 Direct 0 0 11.1.1.2 Vlan1

20.1.1.0/24 ISIS 15 74 11.1.1.2 Vlan1

21.1.1.0/24 ISIS 15 74 11.1.1.2 Vlan1

21.1.1.2/32 ISIS 15 74 11.1.1.2 Vlan1

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

Issuing the display ip routing-table command on PE 3 and PE 4, you should see that the internal routes of the Level 2 carrier network are present in the public network routing tables. Takes PE 3 as an example:

[PE3] display ip routing-table

Routing Tables: Public

Destinations : 11 Routes : 11

Destination/Mask Proto Pre Cost NextHop Interface

1.1.1.9/32 Direct 0 0 127.0.0.1 InLoop0

2.2.2.9/32 ISIS 15 10 10.1.1.2 Vlan2

5.5.5.9/32 ISIS 15 84 10.1.1.2 Vlan2

6.6.6.9/32 ISIS 15 84 10.1.1.2 Vlan2

10.1.1.0/24 Direct 0 0 10.1.1.1 Vlan2

10.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

10.1.1.2/32 Direct 0 0 10.1.1.2 Vlan2

11.1.1.0/24 ISIS 15 20 10.1.1.2 Vlan2

20.1.1.0/24 ISIS 15 84 10.1.1.2 Vlan2

21.1.1.0/24 ISIS 15 84 10.1.1.2 Vlan2

21.1.1.2/32 ISIS 15 84 10.1.1.2 Vlan2

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

Issuing the display ip routing-table vpn-instance command on PE 3 and PE 4, you should see that the routes of the remote VPN customers are present in the VPN routing tables. Takes PE 3 as an example:

[PE3] display ip routing-table vpn-instance vpn1

Routing Tables: vpn1

Destinations : 3 Routes : 3

Destination/Mask Proto Pre Cost NextHop Interface

100.1.1.0/24 Direct 0 0 100.1.1.2 Vlan1

100.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0

120.1.1.0/24 BGP 255 0 6.6.6.9 NULL0

PE 3 and PE 4 should be able to ping each other:

[PE3] ping 20.1.1.2

PING 20.1.1.2: 56 data bytes, press CTRL_C to break

Reply from 20.1.1.2: bytes=56 Sequence=1 ttl=252 time=127 ms

Reply from 20.1.1.2: bytes=56 Sequence=2 ttl=252 time=97 ms

Reply from 20.1.1.2: bytes=56 Sequence=3 ttl=252 time=83 ms

Reply from 20.1.1.2: bytes=56 Sequence=4 ttl=252 time=70 ms

Reply from 20.1.1.2: bytes=56 Sequence=5 ttl=252 time=60 ms

--- 20.1.1.2 ping statistics ---

5 packet(s) transmitted

5 packet(s) received

0.00% packet loss

round-trip min/avg/max = 60/87/127 ms

CE 3 and CE 4 should be able to ping each other:

[CE3] ping 120.1.1.1

PING 120.1.1.1: 56 data bytes, press CTRL_C to break

Reply from 120.1.1.1: bytes=56 Sequence=1 ttl=252 time=102 ms

Reply from 120.1.1.1: bytes=56 Sequence=2 ttl=252 time=69 ms

Reply from 120.1.1.1: bytes=56 Sequence=3 ttl=252 time=105 ms

Reply from 120.1.1.1: bytes=56 Sequence=4 ttl=252 time=88 ms

Reply from 120.1.1.1: bytes=56 Sequence=5 ttl=252 time=87 ms

--- 120.1.1.1 ping statistics ---

5 packet(s) transmitted

5 packet(s) received

0.00% packet loss

round-trip min/avg/max = 69/90/105 ms

1.11.6 Example for Configuring HoVPN

I. Network requirements

There are two levels of networks, the backbone and the MPLS VPN networks, as shown in Figure 1-23.

l SPEs act as PEs to allow MPLS VPNs to access the backbone.

l UPEs act as PEs of the MPLS VPNs to allow end users to access the VPNs.

l Performance requirements for the UPEs are lower than those for the SPEs.

II. Network diagram

Device	Interface	IP address	Device	Interface	IP address
CE 1	Vlan-int1	10.2.1.1/24	CE 3	Vlan-int1	10.1.1.1/24
CE 2	Vlan-int1	10.4.1.1/24	CE 4	Vlan-int1	10.3.1.1/24
UPE 1	Loop1	1.1.1.9/32	UPE 2	Loop1	4.4.4.9/32
	Vlan-int1	172.1.1.1/24		Vlan-int1	172.2.1.1/24
	Vlan-int2	10.2.1.2/24		Vlan-int2	10.1.1.2/24
	Vlan-int3	10.4.1.2/24		Vlan-int3	10.3.1.2/24
SPE 1	Loop1	2.2.2.9/32	SPE 2	Loop1	3.3.3.9/32
	Vlan-int1	172.1.1.2/24		Vlan-int1	172.2.1.2/24
	Vlan-int2	180.1.1.1/24		Vlan-int2	180.1.1.2/24

Figure 1-23 Configure HoVPN

III. Configuration procedure

1) Configure UPE 1

<Sysname> system-view

[Sysname] sysname UPE1

[UPE1] interface loopback 1

[UPE1-LoopBack1] ip address 1.1.1.9 32

[UPE1-LoopBack1] quit

[UPE1] mpls lsr-id 1.1.1.9

[UPE1] mpls

[UPE1-mpls] quit

[UPE1] mpls ldp

[UPE1-mpls-ldp] quit

[UPE1] interface vlan-interface 1

[UPE1-Vlan-interface1] ip address 172.1.1.1 24

[UPE1-Vlan-interface1] mpls

[UPE1-Vlan-interface1] mpls ldp

[UPE1-Vlan-interface1] quit

[UPE1] ospf

[UPE1-ospf-1] area 0

[UPE1-ospf-1-area-0.0.0.0] network 172.1.1.0 0.0.0.255

[UPE1-ospf-1-area-0.0.0.0] network 1.1.1.9 0.0.0.0

[UPE1-ospf-1-area-0.0.0.0] quit

[UPE1-ospf-1] quit

[UPE1] ip vpn-instance vpn1

[UPE1-vpn-instance-vpn1] route-distinguisher 100:1

[UPE1-vpn-instance-vpn1] vpn-target 100:1 both

[UPE1-vpn-instance-vpn1] quit

[UPE1] ip vpn-instance vpn2

[UPE1-vpn-instance-vpn2] route-distinguisher 100:2

[UPE1-vpn-instance-vpn2] vpn-target 100:2 both

[UPE1-vpn-instance-vpn2] quit

[UPE1] interface vlan-interface 2

[UPE1-Vlan-interface2] ip binding vpn-instance vpn1

[UPE1-Vlan-interface2] ip address 10.2.1.2 24

[UPE1-Vlan-interface2] quit

[UPE1] interface vlan-interface 3

[UPE1-Vlan-interface3] ip binding vpn-instance vpn2

[UPE1-Vlan-interface3] ip address 10.4.1.2 24

[UPE1-Vlan-interface3] quit

[UPE1] bgp 100

[UPE1-bgp] peer 2.2.2.9 as-number 100

[UPE1-bgp] import-route direct

[UPE1-bgp] ipv4-family vpnv4

[UPE1-bgp-af-vpnv4] peer 2.2.2.9 enable

[UPE1-bgp-af-vpnv4] quit

[UPE1-bgp] ipv4-family vpn-instance vpn1

[UPE1-bgp-vpn1] peer 10.2.1.1 as-number 65410

[UPE1-bgp-vpn1] import-route direct

[UPE1-bgp-vpn1] quit

[UPE1-bgp] ipv4-family vpn-instance vpn2

[UPE1-bgp-vpn1] peer 10.4.1.1 as-number 65420

[UPE1-bgp-vpn1] import-route direct

[UPE1-bgp-vpn1] quit

[UPE1-bgp] quit

2) Configure CE 1

<Sysname> system-view

[Sysname] sysname CE1

[CE1] interface vlan-interface 1

[CE1-Vlan-interface1] ip address 10.2.1.1 255.255.255.0

[CE1-Vlan-interface1] quit

[CE1] bgp 65410

[CE1-bgp] peer 10.2.1.2 as-number 100

[CE1-bgp] import-route direct

[CE1] quit

3) Configure CE 2

<Sysname> system-view

[Sysname] sysname CE2

[CE2] interface vlan-interface 1

[CE2-Vlan-interface1] ip address 10.4.1.1 255.255.255.0

[CE2-Vlan-interface1] quit

[CE2] bgp 65420

[CE2-bgp] peer 10.4.1.2 as-number 100

[CE2-bgp] import-route direct

[CE2] quit

4) Configure UPE 2

<Sysname> system-view

[Sysname] sysname UPE2

[UPE2] interface loopback 1

[UPE2-Loopback1] ip address 4.4.4.9 32

[UPE2-Loopback1] quit

[UPE2] mpls lsr-id 4.4.4.9

[UPE2] mpls

[UPE2-mpls] quit

[UPE2] mpls ldp

[UPE2-mpls-ldp] quit

[UPE2] interface vlan-interface 1

[UPE2-Vlan-interface1] ip address 172.2.1.1 24

[UPE2-Vlan-interface1] mpls

[UPE2-Vlan-interface1] mpls ldp

[UPE2-Vlan-interface1] quit

[UPE2] ospf

[UPE2-ospf-1] area 0

[UPE2-ospf-1-area-0.0.0.0] network 172.2.1.0 0.0.0.255

[UPE2-ospf-1-area-0.0.0.0] network 4.4.4.9 0.0.0.0

[UPE2-ospf-1-area-0.0.0.0] quit

[UPE2-ospf-1] quit

[UPE2] ip vpn-instance vpn1

[UPE2-vpn-instance-vpn1] route-distinguisher 300:1

[UPE2-vpn-instance-vpn1] vpn-target 100:1 both

[UPE2-vpn-instance-vpn1] quit

[UPE2] ip vpn-instance vpn2

[UPE2-vpn-instance-vpn2] route-distinguisher 400:2

[UPE2-vpn-instance-vpn2] vpn-target 100:2 both

[UPE2-vpn-instance-vpn2] quit

[UPE2] interface vlan-interface 2

[UPE2-Vlan-interface2] ip binding vpn-instance vpn1

[UPE2-Vlan-interface2] ip address 10.1.1.2 24

[UPE2-Vlan-interface2] quit

[UPE2] interface vlan-interface 3

[UPE2-Vlan-interface3] ip binding vpn-instance vpn2

[UPE2-Vlan-interface3] ip address 10.3.1.2 24

[UPE2-Vlan-interface3] quit

[UPE2] bgp 100

[UPE2-bgp] peer 3.3.3.9 as-number 100

[UPE2-bgp] import-route direct

[UPE2-bgp] ipv4-family vpnv4

[UPE2-bgp-af-vpnv4] peer 3.3.3.9 enable

[UPE2-bgp-af-vpnv4] quit

[UPE2-bgp] ipv4-family vpn-instance vpn1

[UPE2-bgp-vpn1] peer 10.1.1.1 as-number 65430

[UPE2-bgp-vpn1] import-route direct

[UPE2-bgp-vpn1] quit

[UPE2-bgp] ipv4-family vpn-instance vpn2

[UPE2-bgp-vpn1] peer 10.3.1.1 as-number 65440

[UPE2-bgp-vpn1] import-route direct

[UPE2-bgp-vpn1] quit

[UPE2-bgp] quit

5) Configure CE 3

<Sysname> system-view

[Sysname] sysname CE3

[CE3] interface vlan-interface 1

[CE3-Vlan-interface1] ip address 10.1.1.1 255.255.255.0

[CE3-Vlan-interface1] quit

[CE3] bgp 65430

[CE3-bgp] peer 10.1.1.2 as-number 100

[CE3-bgp] import-route direct

[CE3] quit

6) Configure CE 4

<Sysname> system-view

[Sysname] sysname CE1

[CE4] interface vlan-interface 1

[CE4-Vlan-interface1] ip address 10.3.1.1 255.255.255.0

[CE4-Vlan-interface1] quit

[CE4] bgp 65440

[CE4-bgp] peer 10.3.1.2 as-number 100

[CE4-bgp] import-route direct

[CE4] quit

7) Configure SPE 1

<Sysname> system-view

[Sysname] sysname SPE1

[SPE1] interface loopback 1

[SPE1-LoopBack1] ip address 2.2.2.9 32

[SPE1-LoopBack1] quit

[SPE1] mpls lsr-id 2.2.2.9

[SPE1] mpls

[SPE1-mpls] quit

[SPE1] mpls ldp

[SPE1-mpls-ldp] quit

[SPE1] interface vlan-interface 1

[SPE1-Vlan-interface1] ip address 172.1.1.2 24

[SPE1-Vlan-interface1] mpls

[SPE1-Vlan-interface1] mpls ldp

[SPE1-Vlan-interface1] quit

[SPE1] interface vlan-interface 2

[SPE1-Vlan-interface2] ip address 180.1.1.1 24

[SPE1-Vlan-interface2] mpls

[SPE1-Vlan-interface2] mpls ldp

[SPE1-Vlan-interface2] quit

[SPE1] ospf

[SPE1-ospf-1] area 0

[SPE1-ospf-1-area-0.0.0.0] network 2.2.2.9 0.0.0.0

[SPE1-ospf-1-area-0.0.0.0] network 172.1.1.0 0.0.0.255

[SPE1-ospf-1-area-0.0.0.0] network 180.1.1.0 0.0.0.255

[SPE1-ospf-1-area-0.0.0.0] quit

[SPE1-ospf-1] quit

[SPE1] ip vpn-instance vpna

[SPE1-vpn-instance-vpna] route-distinguisher 500:1

[SPE1-vpn-instance-vpna] vpn-target 100:1 both

[SPE1-vpn-instance-vpna] quit

[SPE1] ip vpn-instance vpnb

[SPE1-vpn-instance-vpnb] route-distinguisher 700:1

[SPE1-vpn-instance-vpnb] vpn-target 100:2 both

[SPE1-vpn-instance-vpnb] quit

[SPE1] bgp 100

[SPE1-bgp] peer 1.1.1.9 as-number 100

[SPE1-bgp] peer 1.1.1.9 connect-interface loopback 1

[SPE1-bgp] peer 1.1.1.9 next-hop-local

[SPE1-bgp] peer 3.3.3.9 as-number 100

[SPE1-bgp] peer 3.3.3.9 connect-interface loopback 1

[SPE1-bgp] ipv4-family vpnv4

[SPE1-bgp-af-vpnv4] peer 3.3.3.9 enable

[SPE1-bgp-af-vpnv4] peer 1.1.1.9 enable

[SPE1-bgp-af-vpnv4] peer 1.1.1.9 upe

[SPE1-bgp-af-vpnv4] peer 1.1.1.9 default-route-advertise vpn-instance vpna

[SPE1-bgp-af-vpnv4] peer 1.1.1.9 default-route-advertise vpn-instance vpnb

[SPE1-bgp-af-vpnv4] quit

[SPE1-bgp]ipv4-family vpn-instance vpna

[SPE1-bgp-vpna] quit

[SPE1-bgp]ipv4-family vpn-instance vpnb

[SPE1-bgp-vpnb] quit

[SPE1-bgp] quit

8) Configure SPE 2

<Sysname> system-view

[Sysname] sysname SPE2

[SPE2] interface loopback 1

[SPE2-LoopBack1] ip address 3.3.3.9 32

[SPE2-LoopBack1] quit

[SPE2] mpls lsr-id 3.3.3.9

[SPE2] mpls

[SPE2-mpls] quit

[SPE2] mpls ldp

[SPE2-mpls-ldp] quit

[SPE2] interface vlan-interface 2

[SPE2-Vlan-interface2] ip address 180.1.1.2 24

[SPE2-Vlan-interface2] mpls

[SPE2-Vlan-interface2] mpls ldp

[SPE2-Vlan-interface2] quit

[SPE2] interface vlan-interface 1

[SPE2-Vlan-interface1] ip address 172.2.1.2 24

[SPE2-Vlan-interface1] mpls

[SPE2-Vlan-interface1] mpls ldp

[SPE2-Vlan-interface1] quit

[SPE2] ospf

[SPE2-ospf-1] area 0

[SPE2-ospf-1-area-0.0.0.0] network 3.3.3.9 0.0.0.0

[SPE2-ospf-1-area-0.0.0.0] network 172.2.1.0 0.0.0.255

[SPE2-ospf-1-area-0.0.0.0] network 180.1.1.0 0.0.0.255

[SPE2-ospf-1-area-0.0.0.0] quit

[SPE2-ospf-1] quit

[SPE2] ip vpn-instance vpna

[SPE2-vpn-instance-vpna] route-distinguisher 600:1

[SPE2-vpn-instance-vpna] vpn-target 100:1 both

[SPE2-vpn-instance-vpna] quit

[SPE2] ip vpn-instance vpnb

[SPE2-vpn-instance-vpnb] route-distinguisher 800:1

[SPE2-vpn-instance-vpnb] vpn-target 100:2 both

[SPE2-vpn-instance-vpnb] quit

# Configure SPE 2 to establish MP-IBGP peer relationship with UPE 2 and to inject VPN routes, and specify UPE 2.

[SPE2] bgp 100

[SPE2-bgp] peer 4.4.4.9 as-number 100

[SPE2-bgp] peer 4.4.4.9 connect-interface loopback 1

[SPE2-bgp] peer 4.4.4.9 next-hop-local

[SPE2-bgp] peer 2.2.2.9 as-number 100

[SPE2-bgp] peer 2.2.2.9 connect-interface loopback 1

[SPE2-bgp] ipv4-family vpnv4

[SPE2-bgp-af-vpnv4] peer 2.2.2.9 enable

[SPE2-bgp-af-vpnv4] peer 4.4.4.9 enable

[SPE2-bgp-af-vpnv4] peer 4.4.4.9 upe

[SPE2-bgp-af-vpnv4] peer 4.4.4.9 default-route-advertise vpn-instance vpna

[SPE2-bgp-af-vpnv4] peer 4.4.4.9 default-route-advertise vpn-instance vpnb

[SPE2-bgp-af-vpnv4] quit

[SPE2-bgp]ipv4-family vpn-instance vpna

[SPE2-bgp-vpna] quit

[SPE2-bgp]ipv4-family vpn-instance vpnb

[SPE2-bgp-vpnb] quit

[SPE2-bgp] quit

1.11.7 Example for Configuring OSPF Sham Links

I. Network requirements

l CE 1 and CE 2 belong to VPN 1 and are respectively connected to PE 1 and PE 2.

l CE 1 and CE 2 are in the same OSPF area.

l VPN traffic between CE 1 and CE 2 is required to be forwarded through the MPLS backbone, instead of any route in the OSPF area.

II. Network diagram

Device	Interface	IP address	Device	Interface	IP address
CE 1	Vlan-int1	100.1.1.1/24	CE 2	Vlan-int1	120.1.1.1/24
	Vlan-int2	20.1.1.1/24		Vlan-int2	30.1.1.2/24
PE 1	Loop1	1.1.1.9/32	PE 2	Loop1	2.2.2.9/32
	Loop10	3.3.3.3/32		Loop10	5.5.5.5/32
	Vlan-int1	100.1.1.2/24		Vlan-int1	120.1.1.2/24
	Vlan-int2	10.1.1.1/24		Vlan-int2	10.1.1.2/24
Switch A	Vlan-int1	20.1.1.2/24
	Vlan-int2	30.1.1.1/24

Figure 1-24 Configure an OSPF sham link

III. Configuration procedure

1) Configure OSPF on the customer networks

Configure conventional OSPF on CE 1 and CE 2 to advertise segment addresses of the interfaces as shown in Figure 1-24. The detailed configuration steps are omitted.

After completing the configurations, CE 1 and CE 2 should be able to learn the OSPF route to the VLAN interface 1 of each other. The following takes CE 1 as an example:

[CE1] display ip routing-table

Routing Tables: Public

Destinations : 9 Routes : 9

Destination/Mask Proto Pre Cost NextHop Interface

20.1.1.0/24 Direct 0 0 20.1.1.1 Vlan2

20.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

20.1.1.2/32 Direct 0 0 20.1.1.2 Vlan2

30.1.1.0/24 OSPF 10 3124 20.1.1.2 Vlan2

100.1.1.0/24 Direct 0 0 100.1.1.1 Vlan1

100.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

120.1.1.0/24 OSPF 10 3125 20.1.1.2 Vlan2

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

2) Configure MPLS L3VPN on the backbone

# Configure MPLS basic capability and MPLS LDP on PE 1 to establish LDP LSPs.

<Sysname> system-view

[Sysname] sysname PE1

[PE1] interface loopback 1

[PE1-LoopBack1] ip address 1.1.1.9 32

[PE1-LoopBack1] quit

[PE1] mpls lsr-id 1.1.1.9

[PE1] mpls

[PE1-mpls] quit

[PE1] mpls ldp

[PE1-mpls-ldp] quit

[PE1] interface vlan-interface 2

[PE1-Vlan-interface2] ip address 10.1.1.1 24

[PE1-Vlan-interface2] mpls

[PE1-Vlan-interface2] mpls ldp

[PE1-Vlan-interface2] quit

# Configure PE 1 to take PE 2 as the MP-IBGP peer.

[PE1] bgp 100

[PE1-bgp] peer 2.2.2.9 as-number 100

[PE1-bgp] peer 2.2.2.9 connect-interface loopback 1

[PE1-bgp] ipv4-family vpnv4

[PE1-bgp-af-vpnv4] peer 2.2.2.9 enable

[PE1-bgp-af-vpnv4] quit

[PE1-bgp] quit

# Configure OSPF on PE 1.

[PE1] ospf 1

[PE1-ospf-1] area 0

[PE1-ospf-1-area-0.0.0.0] network 1.1.1.9 0.0.0.0

[PE1-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255

[PE1-ospf-1-area-0.0.0.0] quit

[PE1-ospf-1] quit

# Configure MPLS basic capability and MPLS LDP on PE 2 to establish LDP LSPs.

<Sysname> system-view

[Sysname] sysname PE2

[PE2] interface loopback 1

[PE2-LoopBack1] ip address 2.2.2.9 32

[PE2-LoopBack1] quit

[PE2] mpls lsr-id 2.2.2.9

[PE2] mpls

[PE2-mpls] quit

[PE2] mpls ldp

[PE2-mpls-ldp] quit

[PE2] interface vlan-interface 2

[PE2-Vlan-interface2] ip address 10.1.1.2 24

[PE2-Vlan-interface2] mpls

[PE2-Vlan-interface2] mpls ldp

[PE2-Vlan-interface2] quit

# Configure PE 2 to take PE 1 as the MP-IBGP peer.

[PE2] bgp 100

[PE2-bgp] peer 1.1.1.9 as-number 100

[PE2-bgp] peer 1.1.1.9 connect-interface loopback 1

[PE2-bgp] ipv4-family vpnv4

[PE2-bgp-af-vpnv4] peer 1.1.1.9 enable

[PE2-bgp-af-vpnv4] quit

[PE2-bgp] quit

# Configure OSPF on PE 2.

[PE2] ospf 1

[PE2-ospf-1] area 0

[PE2-ospf-1-area-0.0.0.0] network 2.2.2.9 0.0.0.0

[PE2-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255

[PE2-ospf-1-area-0.0.0.0] quit

[PE2-ospf-1] quit

3) Configure PEs to allow CEs to access the network

# Configure PE 1 to allow CE 1 to access the network.

[PE1] ip vpn-instance vpn1

[PE1-vpn-instance-vpn1] route-distinguisher 100:1

[PE1-vpn-instance-vpn1] vpn-target 1:1

[PE1-vpn-instance-vpn1] quit

[PE1] interface vlan-interface 1

[PE1-Vlan-interface1] ip binding vpn-instance vpn1

[PE1-Vlan-interface1] ip address 100.1.1.2 24

[PE1-Vlan-interface1] quit

[PE1] ospf 100 vpn-instance vpn1

[PE1-ospf-100] domain-id 10

[PE1-ospf-100] area 1

[PE1-ospf-100-area-0.0.0.1] network 100.1.1.0 0.0.0.255

[PE1-ospf-100-area-0.0.0.1] quit

[PE1-ospf-100] quit

[PE2] bgp 100

[PE1-bgp] ipv4-family vpn-instance vpn1

[PE1-bgp-vpn1] import-route direct

[PE1-bgp-vpn1] quit

[PE1-bgp] quit

# Configure PE 2 to allow CE 2 to access the network.

[PE2] ip vpn-instance vpn1

[PE2-vpn-instance-vpn1] route-distinguisher 100:2

[PE2-vpn-instance-vpn1] vpn-target 1:1

[PE2-vpn-instance-vpn1] quit

[PE2] interface vlan-interface 1

[PE2-Vlan-interface1] ip binding vpn-instance vpn1

[PE2-Vlan-interface1] ip address 120.1.1.2 24

[PE2-Vlan-interface1] quit

[PE2] ospf 100 vpn-instance vpn1

[PE2-ospf-100] domain-id 10

[PE2-ospf-100] area 1

[PE2-ospf-100-area-0.0.0.1] network 120.1.1.0 0.0.0.255

[PE2-ospf-100-area-0.0.0.1] quit

[PE2-ospf-100] quit

[PE2] bgp 100

[PE2-bgp] ipv4-family vpn-instance vpn1

[PE2-bgp-vpn1] import-route direct

[PE2-bgp-vpn1] quit

[PE2-bgp] quit

After completing the above configurations, if you issue the display ip routing-table vpn-instance command on the PEs, you should see that the path to the peer CE is along the OSPF route across the customer networks, instead of the BGP route across the backbone. Take PE 1 as an example:

[PE1] display ip routing-table vpn-instance vpn1

Routing Tables: vpn1

Destinations : 5 Routes : 5

Destination/Mask Proto Pre Cost NextHop Interface

20.1.1.0/24 OSPF 10 1563 100.1.1.1 Vlan1

30.1.1.0/24 OSPF 10 3125 100.1.1.1 Vlan1

100.1.1.0/24 Direct 0 0 100.1.1.2 Vlan1

100.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0

120.1.1.0/24 OSPF 10 3126 100.1.1.1 Vlan1

4) Configure a sham link

# Configure PE 1.

[PE1] interface loopback 10

[PE1-LoopBack10] ip binding vpn-instance vpn1

[PE1-LoopBack10] ip address 3.3.3.3 32

[PE1-LoopBack10] quit

[PE1] ospf 100

[PE1-ospf-100] area 1

[PE1-ospf-100-area-0.0.0.1] sham-link 3.3.3.3 5.5.5.5 cost 10

[PE1-ospf-100-area-0.0.0.1] quit

[PE1-ospf-100] quit

# Configure PE 2.

[PE2] interface loopback 10

[PE2-LoopBack10] ip binding vpn-instance vpn1

[PE2-LoopBack10] ip address 5.5.5.5 32

[PE2-LoopBack10] quit

[PE2] ospf 100

[PE2-ospf-100] area 1

[PE2-ospf-100-area-0.0.0.1] sham-link 5.5.5.5 3.3.3.3 cost 10

[PE2-ospf-100-area-0.0.0.1] quit

[PE2-ospf-100] quit

After completing the above configurations, if you issue the display ip routing-table vpn-instance command again on the PEs, you should see that the path to the peer CE is now along the BGP route across the backbone, and that a route to the sham link destination address is present. Take PE 1 as an example:

[PE1] display ip routing-table vpn-instance vpn1

Routing Tables: vpn1

Destinations : 6 Routes : 6

Destination/Mask Proto Pre Cost NextHop Interface

3.3.3.3/32 Direct 0 0 127.0.0.1 InLoop0

5.5.5.5/32 BGP 255 0 2.2.2.9 NULL0

20.1.1.0/24 OSPF 10 1563 100.1.1.1 Vlan1

100.1.1.0/24 Direct 0 0 100.1.1.2 Vlan1

100.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0

120.1.1.0/24 BGP 255 0 2.2.2.9 NULL0

Issuing the display ip routing-table command on the CEs, you should see that the cost of the OSPF route to the peer CE is now 10 (the cost configured for the sham link), and that the next hop is now the VLAN interface 1 connected to the PE. This means that VPN traffic to the peer will be forwarded over the backbone. Takes CE 1 as an example:

[CE1] display ip routing-table

Routing Tables: Public

Destinations : 9 Routes : 9

Destination/Mask Proto Pre Cost NextHop Interface

20.1.1.0/24 Direct 0 0 20.1.1.1 Vlan2

20.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

20.1.1.2/32 Direct 0 0 20.1.1.2 Vlan2

30.1.1.0/24 OSPF 10 1574 100.1.1.2 Vlan1

100.1.1.0/24 Direct 0 0 100.1.1.1 Vlan1

100.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

120.1.1.0/24 OSPF 10 12 100.1.1.2 Vlan1

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

Issuing the display ospf sham-link command on the PEs, you should see the established sham link. Takes PE 1 as an example:

[PE1] display ospf sham-link

OSPF Process 100 with Router ID 100.1.1.2

Sham Link:

Area RouterId Source-IP Destination-IP State Cost

0.0.0.1 100.1.1.2 3.3.3.3 5.5.5.5 P-2-P 10

Issuing the display ospf sham-link area command, you should see that the status of the peer is Full:

[PE1] display ospf sham-link area 1

OSPF Process 100 with Router ID 100.1.1.2

Sham-Link: 3.3.3.3 --> 5.5.5.5

Neighbour State: Full

Area: 0.0.0.1

Cost: 10 State: P-2-P, Type: Sham

Timers: Hello 10 , Dead 40 , Retransmit 5 , Transmit Delay 1

1.11.8 Example for Configuring BGP AS Number Substitution

I. Network requirements

As shown in Figure 1-25, CE 1 and CE 2 belong to VPN 1 and are connected to PE 1 and PE 2 respectively. In addition, they use the same AS number 600.

II. Network diagram

Device	Interface	IP address	Device	Interface	IP address
CE 1	Vlan-int1	10.1.1.1/24	P	Loop1	2.2.2.9/32
	Vlan-int2	100.1.1.1/24		Vlan-int1	30.1.1.1/24
PE 1	Loop1	1.1.1.9/32		Vlan-int2	20.1.1.2/24
	Vlan-int1	10.1.1.2/24	PE 2	Loop1	3.3.3.9/32
	Vlan-int2	20.1.1.1/24		Vlan-int1	30.1.1.2/24
CE 2	Vlan-int1	10.2.1.1/24		Vlan-int2	10.2.1.2/24
	Vlan-int2	200.1.1.1/24

Figure 1-25 Configure BGP AS number substitution

III. Configuration procedure

1) Configuring basic MPLS L3VPN

l Configure OSPF on the MPLS backbone to allow the PEs and P device to learn the routes of the loopback interfaces from each other.

l Configure MPLS basic capability and MPLS LDP on the MPLS backbone to establish LDP LSPs.

l Establish MP-IBGP neighbor relationship between the PEs to advertise VPN IPv4 routes.

l Configure the VPN instance of VPN 2 on PE 2 to allow CE 2 to access the network.

l Configure the VPN instance of VPN 1 on PE 1 to allow CE 1 to access the network.

l Configure BGP between PE 1 and CE 1, and between PE 2 and CE 2 to inject routes of CEs into PEs.

After completing the above configurations, if you issue the display ip routing-table command on CE 2, you should see that CE 2 has learned the route to network segment 10.1.1.0/24, where the interface used by CE 1 to access PE 1 resides; but has not learned the route to the VPN (100.1.1.0/24) behind CE 1. You should see the similar situation on CE 1.

[CE2] display ip routing-table

Routing Tables: Public

Destinations : 8 Routes : 8

Destination/Mask Proto Pre Cost NextHop Interface

10.1.1.0/24 BGP 255 0 10.2.1.2 Vlan1

10.1.1.1/32 BGP 255 0 10.2.1.2 Vlan1

10.2.1.0/24 Direct 0 0 10.2.1.1 Vlan1

10.2.1.1/32 Direct 0 0 127.0.0.1 InLoop0

10.2.1.2/32 Direct 0 0 10.2.1.2 Vlan1

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

200.1.1.0/24 Direct 0 0 200.1.1.1 InLoop0

200.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

Issuing the display ip routing-table vpn-instance command on the PEs, you should see the route to the VPN behind the peer CE. Takes PE 2 as an example:

[PE2] display ip routing-table vpn-instance vpn1

Routing Tables: vpn1

Destinations : 7 Routes : 7

Destination/Mask Proto Pre Cost NextHop Interface

10.1.1.0/24 BGP 255 0 1.1.1.9 NULL0

10.1.1.1/32 BGP 255 0 1.1.1.9 NULL0

10.2.1.0/24 Direct 0 0 10.2.1.2 Vlan1

10.2.1.1/32 Direct 0 0 10.2.1.1 Vlan1

10.2.1.2/32 Direct 0 0 127.0.0.1 InLoopBack0

100.1.1.1/32 BGP 255 0 1.1.1.9 NULL0

200.1.1.1/32 BGP 255 0 10.2.1.1 Vlan1

Enabling BGP update packet debugging on PE 2, you should see that PE 2 advertises the route to 100.1.1.1/32, and the AS_PATH is 100 600.

<PE2> terminal monitor

<PE2> terminal debugging

<PE2> debugging bgp update vpn-instance vpn1 verbose

<PE2> refresh bgp vpn-instance vpn1 all export

*Jan 30 17:21:11:363 2007 PE2 RM/7/RMDEBUG:

BGP.vpn1: Send UPDATE to 10.2.1.1 for following destinations :

Origin : Incomplete

AS Path : 100 600

Next Hop : 10.2.1.2

100.1.1.1/32,

Issuing the display bgp routing-table peer received-routes command on CE 2, you should see that CE 2 did not receive the route to 100.1.1.1/32.

[CE2] display bgp routing-table peer 10.2.1.2 received-routes

Total Number of Routes: 4

BGP Local router ID is 10.2.1.1

Status codes: * - valid, > - best, d - damped,

h - history, i - internal, s - suppressed, S - Stale

Origin : i - IGP, e - EGP, ? - incomplete

Network NextHop MED LocPrf PrefVal Path/Ogn

*> 10.1.1.0/24 10.2.1.2 0 100?

*> 10.1.1.1/32 10.2.1.2 0 100?

* 10.2.1.0/24 10.2.1.2 0 0 100?

* 10.2.1.1/32 10.2.1.2 0 0 100?

2) Configure BGP AS number substitution

# Configure BGP AS number substitution on PE 2.

[PE2] bgp 100

[PE2-bgp] ipv4-family vpn-instance vpn1

[PE2-bgp-vpn1] peer 10.2.1.1 substitute-as

You should see that among the routes advertised by PE 2 to CE 2, the AS_PATH of 100.1.1.1/32 has changed from 100 600 to 100 100:

*Jan 30 17:11:30:362 2007 PE2 RM/7/RMDEBUG:

BGP.vpn1: Send UPDATE to 10.2.1.1 for following destinations :

Origin : Incomplete

AS Path : 100 100

Next Hop : 10.2.1.2

100.1.1.1/32

Display again the routing information that CE 2 receives and the routing table:

[CE2] display bgp routing-table peer 10.2.1.2 received-routes

Total Number of Routes: 5

BGP Local router ID is 10.2.1.1

Status codes: * - valid, > - best, d - damped,

h - history, i - internal, s - suppressed, S - Stale

Origin : i - IGP, e - EGP, ? - incomplete

Network NextHop MED LocPrf PrefVal Path/Ogn

*> 10.1.1.0/24 10.2.1.2 0 100?

*> 10.1.1.1/32 10.2.1.2 0 100?

* 10.2.1.0/24 10.2.1.2 0 0 100?

* 10.2.1.1/32 10.2.1.2 0 0 100?

*> 100.1.1.1/32 10.2.1.2 0 100 100?

[CE2] display ip routing-table

Routing Tables: Public

Destinations : 9 Routes : 9

Destination/Mask Proto Pre Cost NextHop Interface

10.1.1.0/24 BGP 255 0 10.2.1.2 Vlan1

10.1.1.1/32 BGP 255 0 10.2.1.2 Vlan1

10.2.1.0/24 Direct 0 0 10.2.1.1 Vlan1

10.2.1.1/32 Direct 0 0 127.0.0.1 InLoop0

10.2.1.2/32 Direct 0 0 10.2.1.2 Vlan1

100.1.1.1/32 BGP 255 0 10.2.1.2 Vlan1

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

200.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

After configuring BGP AS substitution on PE 1 too, the interfaces of CE 1 and CE 2 should be able to ping each other:

[CE1] ping –a 100.1.1.1 200.1.1.1

PING 200.1.1.1: 56 data bytes, press CTRL_C to break

Reply from 200.1.1.1: bytes=56 Sequence=1 ttl=253 time=109 ms

Reply from 200.1.1.1: bytes=56 Sequence=2 ttl=253 time=67 ms

Reply from 200.1.1.1: bytes=56 Sequence=3 ttl=253 time=66 ms

Reply from 200.1.1.1: bytes=56 Sequence=4 ttl=253 time=85 ms

Reply from 200.1.1.1: bytes=56 Sequence=5 ttl=253 time=70 ms

--- 200.1.1.1 ping statistics ---

5 packet(s) transmitted

5 packet(s) received

0.00% packet loss

round-trip min/avg/max = 66/79/109 ms

H3C S9500 Operation Manual-Release2132[V2.03]-05 MPLS VPN Volume

1.1 MPLS L3VPN Overview

1.1.1 Introduction to MPLS L3VPN

1.1.2 MPLS L3VPN Concepts

I. Site

II. Address space overlapping

III. VPN instance

IV. VPN-IPv4 address

V. VPN target attributes

VI. MP-BGP

VII. Routing policy

VIII. Tunneling policy

1.1.3 MPLS L3VPN Packet Forwarding

1.1.4 MPLS L3VPN Networking Schemes

I. Basic VPN networking scheme

II. Hub and spoke networking scheme

III. Extranet networking scheme

1.1.5 MPLS L3VPN Routing Information Advertisement

I. Routing information exchange from the local CE to the ingress PE

II. Routing information exchange from the ingress PE to the egress PE

III. Routing information exchange from the egress PE to the remote CE

1.1.6 Carrier’s Carrier

I. Introduction to carrier's carrier

II. Implementation of carrier’s carrier

I. Inter-provider VPN option A

II. Inter-provider VPN option B

III. Inter-provider VPN option C

1.1.8 HoVPN

I. Background

II. Implementation of HoVPN

1.1.9 OSPF VPN Extension

I. OSPF multi-instance on PE

II. Sham link

III. Multi-VPN-Instance CE

1.1.10 BGP AS Number Substitution

1.2 MPLS L3VPN Configuration Task List

1.3 Configuring VPN Instances

1.3.1 Creating a VPN Instance

1.3.4 Configuring a Tunneling Policy of a VPN Instance

I. Configuring a tunneling policy

II. Associating a tunneling policy with the VPN instance

1.4 Configuring Basic MPLS L3VPN

1.4.2 Configuring a VPN Instance

1.4.3 Configuring Route Advertisement between PE and CE

I. Configuring static routes between PEs and CEs

II. Configuring RIP between PE and CE

IV. Configuring IS-IS between PE and CE

V. Configuring EBGP Between PE and CE

1.4.4 Configuring Route Advertisement Between PEs

I. Configuring common routing features for all types of subaddress families

II. Configuring specific routing features for BGP-VPNv4 subaddress family

1.5 Configuring Inter-Provider VPN

1.5.1 Configuration Prerequisites

I. Configuring the PEs

II. Configuring the ASBR PEs

III. Configuring the routing policy

1.6 Configuring HoVPN

1.6.2 Configuring HoVPNs

1.7 Configuring OSPF Sham Link

1.7.2 Configuring a Loopback Interface

1.7.3 Advertising Routes of a Loopback Interface

1.7.4 Configuring a Sham Link

1.8 Configuring Multi-VPN-instance CE

1.8.2 Configuration Procedure

1.9 Configuring BGP AS Number Substitution

1.10 Displaying and Maintaining MPLS L3VPN

1.10.1 Resetting BGP Connections

1.10.2 Displaying and Maintaining MPLS L3VPN

1.11 MPLS L3VPN Configuration Example

1.11.1 Example for Configuring MPLS L3VPNs

I. Network requirements

II. Network diagram

III. Configuration procedure

1.11.2 Example for Configuring Inter-Provider VPN Option A

I. Network requirements

II. Network diagram

III. Configuration procedure

1.11.3 Example for Configuring Inter-Provider VPN Option B

I. Network requirements

II. Network diagram