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- Table of Contents
-
- H3C S9500 Operation Manual-Release2132[V2.03]-03 IP Routing Volume
- 00-1Cover
- 01-IP Routing Overview
- 02-BGP Configuration
- 03-IS-IS Configuration
- 04-OSPF Configuration
- 05-RIP Configuration
- 06-Routing Policy Configuration
- 07-Static Routing Configuration
- 08-IPv6 BGP Configuration
- 09-IPv6 IS-IS Configuration
- 10-IPv6 OSPFv3 Configuration
- 11-IPv6 RIPng Configuration
- 12-IPv6 Static Routing Configuration
- Related Documents
-
| Title | Size | Download |
|---|---|---|
| 05-RIP Configuration | 208.75 KB |
Table of Contents
1.2 Configuring RIP Basic Functions
1.2.1 Configuration Prerequisites
1.3 Configuring RIP Advanced Functions
1.3.1 Configuring an Additional Routing Metric
1.3.2 Configuring RIP-2 Route Summarization
1.3.3 Disabling Host Route Reception
1.3.4 Advertising a Default Route
1.3.5 Configuring Inbound/Outbound Route Filtering Policies
1.3.6 Configuring a Priority for RIP
1.3.7 Configuring RIP Route Redistribution
1.4 Optimizing the RIP Network
1.4.2 Configuring the Split Horizon and Poison Reverse
1.4.3 Configuring the Maximum Number of Load Balanced Routes
1.4.4 Configuring RIP Message Check
1.4.5 Configuring RIP-2 Message Authentication
1.4.6 Configuring a RIP Neighbor
1.4.8 Configuring RIP-to-MIB Binding
1.5 Displaying and Maintaining RIP Configuration
1.6 RIP Configuration Examples
1.6.1 Configuring the RIP Version
1.6.2 Configuring RIP Route Redistribution
1.7 Troubleshooting RIP Configuration
1.7.2 Route Oscillation Occurred
Chapter 1 RIP Configuration
& Note:
The term “router” in this document refers to a router in a generic sense or an Ethernet switch running routing protocols.
When configuring RIP, go to these sections for information you are interested in:
l Configuring RIP Basic Functions
l Configuring RIP Advanced Functions
l Displaying and Maintaining RIP Configuration
l Troubleshooting RIP Configuration
1.1 RIP Overview
RIP is a simple Interior Gateway Protocol (IGP), mainly used in small-sized networks, such as academic networks and simple structured LANs. RIP is not applicable to complex networks.
RIP is still widely used in practical networking due to easier implementation, configuration and maintenance than OSPF and IS-IS.
1.1.1 RIP Working Mechanism
I. Basic concept of RIP
RIP is a Distance-Vector-based routing protocol, using UDP packets for exchanging information through port 520.
RIP uses a hop count to measure the distance to a destination. The hop count is known as metric. The hop count from a router to its directly connected network is 0. The hop count from one router to a directly connected router is 1. To limit convergence time, the range of RIP metric value is from 0 to 15. A metric value of 16 (or bigger) is considered infinite, which means the destination network is unreachable. That is why RIP is not suitable for large-scaled networks.
RIP prevents routing loops by implementing the split horizon and poison reverse functions.
II. RIP routing table
Each RIP router has a routing table containing routing entries of all reachable destinations, and each routing entry contains:
l Destination address: IP address of a host or a network.
l Next hop: IP address of the adjacent router’s interface to reach the destination.
l Egress interface: Packet outgoing interface.
l Metric: Cost from the local router to the destination.
l Route time: Time elapsed since the routing entry was last updated. The time is reset to 0 every time the routing entry is updated.
l Route tag: Identifies a route, used in routing policy to flexibly control routes. For information about routing policy, refer to Routing Policy Configuration in IP Routing Volume.
III. RIP initialization and running procedure
The following procedure describes how RIP works.
1) After RIP is enabled, the router sends Request messages to neighboring routers. Neighboring routers return Response messages including all information about their routing tables.
2) The router updates its local routing table, and broadcasts the triggered update messages to its neighbors. All routers on the network do the same to keep the latest routing information.
3) RIP ages out timed out routes by adopting an aging mechanism to keep only valid routes.
IV. RIP timers
RIP employs four timers, Update, Timeout, Suppress, and Garbage-Collect.
l The update timer defines the interval between routing updates.
l The timeout timer defines the route aging time. If no update for a route is received after the aging time elapses, the metric of the route is set to 16 in the routing table.
l The suppress timer defines how long a RIP route stays in the suppressed state. When the metric of a route is 16, the route enters the suppressed state. In the suppressed state, only routes which come from the same neighbor and whose metric is less than 16 will be received by the router to replace unreachable routes.
l The garbage-collect timer defines the interval from when the metric of a route becomes 16 to when it is deleted from the routing table. During the Garbage-Collect timer length, RIP advertises the route with the routing metric set to 16. If no update is announced for that route after the Garbage-Collect timer expires, the route will be deleted from the routing table.
V. Routing loops prevention
RIP is a distance-vector (D-V) based routing protocol. Since a RIP router advertises its own routing table to neighbors, routing loops may occur.
RIP uses the following mechanisms to prevent routing loops.
l Counting to infinity. The metric value of 16 is defined as unreachable. When a routing loop occurs, the metric value of the route will increment to 16.
l Split horizon. A router does not send the routing information learned from a neighbor to the neighbor to prevent routing loops and save the bandwidth.
l Poison reverse. A router sets the metric of routes received from a neighbor to 16 and sends back these routes to the neighbor to help delete useless information from the neighbor’s routing table.
l Triggered updates. A router advertises updates once the metric of a route is changed rather than after the update period expires to speed up the network convergence.
1.1.2 RIP Version
RIP has two versions, RIP-1 and RIP-2.
RIP-1, a Classful Routing Protocol, supports message advertisement via broadcast only. RIP-1 protocol messages do not carry mask information, which means it can only recognize routing information of natural networks such as Class A, B, C. That is why RIP-1 does not support discontiguous subnet.
RIP-2 is a Classless Routing Protocol. Compared with RIP-1, RIP-2 has the following advantages.
l Supporting route tags. The route tag is used in routing policies to flexibly control routes.
l Supporting masks, route summarization and classless inter-domain routing (CIDR).
l Supporting designated next hop to select the best next hop on broadcast networks.
l Supporting multicast routing update to reduce resource consumption.
l Supporting Plain text authentication and MD5 authentication to enhance security.
& Note:
RIP-2 has two types of message transmission: broadcast and multicast. Multicast is the default type using 224.0.0.9 as the multicast address. The interface working in the RIP-2 broadcast mode can also receive RIP-1 messages.
1.1.3 RIP Message Format
I. RIP-1 message format
A RIP message consists of the Header and up to 25 route entries.
Figure 1-1 shows the format of RIP-1 message.
Figure 1-1 RIP-1 Message Format
l Command: The type of message. 1 indicates Request, 2 indicates Response.
l Version: The version of RIP, 0x01 for RIP-1.
l AFI: Address Family Identifier, 2 for IP.
l IP Address: Destination IP address of the route; can be a natural network, subnet or a host address.
l Metric: Cost of the route.
II. RIP-2 message format
The format of RIP-2 message is similar with RIP-1. Figure 1-2 shows it.
Figure 1-2 RIP-2 Message Format
The differences from RIP-1 are stated as following.
l Version: Version of RIP. For RIP-2 the value is 0x02.
l Route Tag: Route Tag.
l IP Address: Destination IP address. It could be a natural network address, subnet address or host address.
l Subnet Mask: Mask of the destination address.
l Next Hop: If set to 0.0.0.0, it indicates that the originator of the route is the best next hop; Otherwise it indicates a next hop better that the originator of the route.
III. RIP-2 authentication
RIP-2 sets the AFI field of the first route entry to 0xFFFF to identify authentication information. See Figure 1-3.
Figure 1-3 RIP-2 Authentication Message
l Authentication Type: 2 represents plain text authentication, while 3 represents MD5.
l Authentication: Authentication data, including password information when plain text authentication is adopted or including key ID, MD5 authentication data length and sequence number when MD5 authentication is adopted.
& Note:
RFC 1723 only defines plain text authentication. For information about MD5 authentication, refer to RFC2082 “RIP-2 MD5 Authentication”.
1.1.4 TRIP
Triggered RIP (TRIP), a RIP extension on WAN, is mainly used in dial-up network.
I. Working mechanism
Routing information is sent in triggered updates rather than periodic broadcasts to reduce the routing management cost the WAN.
l Only when data in the routing table changes or the next hop is unreachable, a routing update message is sent.
l Since the periodic update delivery is canceled, an acknowledgement and retransmission mechanism is required to guarantee successful updates transmission on WAN.
II. Message types
RIP use three new types of message which are identified by the value of the Command filed.
l Update Request (type value 9): Requests needed routes from the peer.
l Update Response (type value 10): Contains the routes requested by the peer.
l Update Acknowledge (type value 11): Acknowledges received Update Response messages.
III. TRIP retransmission mechanism
l If receiving no Update Responses after sending an Update Request, a router sends the request again after a specified interval. If still receiving no Update Response after the upper limit for sending requests is reached, the router considers the neighbor unreachable.
l If receiving no Update Acknowledge after sending an Update Response, a router sends the Update Response again after a specified interval. If still receiving no Update Acknowledge after the upper limit for sending Update Responses is reached, the router considers the neighbor unreachable.
1.1.5 RIP Features Supported
The current implementation supports the following RIP features.
l RIP-1 and RIP-2
l RIP Multi-instance. This means that RIP can serve as an internal VPN routing protocol, running between CE and PE on the BGP/MPLS VPN network. For related information, refer to BGP&MPLS VPN Configuration.
l TRIP
1.1.6 Protocols and Standards
l RFC 1058: Routing Information Protocol
l RFC 1723: RIP Version 2 - Carrying Additional Information
l RFC 1721: RIP Version 2 Protocol Analysis
l RFC 1722: RIP Version 2 Protocol Applicability Statement
l RFC 1724: RIP Version 2 MIB Extension
l RFC 2082: RIP-2 MD5 Authentication
l RFC 2091: Triggered Extensions to RIP to Support Demand Circuits
1.2 Configuring RIP Basic Functions
1.2.1 Configuration Prerequisites
Before configuring RIP features, finish the following tasks.
l Configure the link layer protocol.
l Configure the IP address on each interface, and make sure all adjacent routers are reachable with each other at the network layer.
1.2.2 Configuration Procedure
I. Enable RIP and specify networks
Follow these steps to enable RIP:
|
Use the command… |
Remarks |
|
|
Enter system view |
system-view |
–– |
|
Enable a RIP process and enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
Required Not enabled by default |
|
Enable RIP on the network of an interface |
network network-address |
Required Disabled by default |
& Note:
l If you make some RIP configurations in interface view before enabling RIP, those configurations will take effect after RIP is enabled.
l RIP runs only on the interfaces residing on the specified networks. Therefore, you need specify the network after enabling RIP to validate RIP on a specific interface.
l You can enable RIP on all interfaces using the command network 0.0.0.0.
II. Configuring the interface behavior
Follow these steps to configure the interface behavior:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Disable an or all interfaces from sending routing updates (the interfaces can still receive updates) |
silent-interface { all | interface-type interface-number } |
Optional All interfaces can send routing updates by default |
|
Return to system view |
quit |
— |
|
Enter interface view |
interface interface-type interface-number |
— |
|
Enable the interface to receive RIP messages |
rip input |
Optional Enabled by default |
|
Enable the interface to send RIP messages |
rip output |
Optional Enabled by default |
III. Configuring a RIP version
You can configure a RIP version in RIP or interface view.
l If neither global nor interface RIP version is configured, the interface sends RIP-1 broadcasts and can receive RIP-1 broadcast and unicast packets, RIP-2 broadcast, multicast, and unicast packets.
l If an interface has no RIP version configured, it uses the global RIP version; otherwise it uses the RIP version configured on it.
l With RIP-1 configured, an interface sends RIP-1 broadcasts, and can receive RIP-1 broadcasts and RIP-1 unicasts.
l With RIP-2 configured, a multicast interface sends RIP-2 multicasts and can receive RIP-2 unicasts, broadcasts and multicasts.
l With RIP-2 configured, a broadcast interface sends RIP-2 broadcasts and can receive RIP-1 unicasts, and broadcasts, RIP-2 broadcasts, multicasts and unicasts.
Follow these steps to configure a RIP version:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] |
–– |
|
Specify a global RIP version |
version { 1 | 2 } |
Optional; RIP-1 by default; If an interface has a RIP version specified, the version takes precedence over the global one. If no RIP version is specified for an interface, the interface can send RIP-1 broadcasts, and receive RIP-1 broadcasts, unicasts, RIP-2 broadcasts, multicasts and unicasts. |
|
Return to system view |
quit |
— |
|
Enter interface view |
interface interface-type interface-number |
–– |
|
Specify a RIP version |
rip version { 1 | 2 [ broadcast | multicast ] } |
Optional |
1.3 Configuring RIP Advanced Functions
In some complex network environments, you need to configure advanced RIP functions.
This section covers the following topics:
l Configuring an Additional Routing Metric
l Configuring RIP-2 Route Summarization
l Disabling Host Route Reception
l Configuring Inbound/Outbound Route Filtering Policies
l Configuring a Priority for RIP
l Configuring RIP Route Redistribution
Before configuring RIP routing feature, finish the following tasks:
l Configure an IP address for each interface, and make sure all routers are reachable.
l Configure basic RIP functions
1.3.1 Configuring an Additional Routing Metric
An additional routing metric can be added to the metric of an inbound/outbound RIP route, namely, the inbound and outbound additional metric.
The outbound additional metric is added to the metric of a sent route, the route’s metric in the routing table is not changed.
The inbound additional metric is added to the metric of a received route before the route is added into the routing table, so the route’s metric is changed.
Follow these steps to configure additional routing metric:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter interface view |
interface interface-type interface-number |
–– |
|
Define an inbound additional routing metric |
rip metricin value |
Optional 0 by default |
|
Define an outbound additional routing metric |
rip metricout value |
Optional 1 by default |
1.3.2 Configuring RIP-2 Route Summarization
The route summarization means that subnet routes in a natural network are summarized with a natural network that is sent to other networks. This function can reduce the size of routing tables.
I. Configure RIP-2 route automatic summarization
Disable RIP-2 route automatic summarization if you want to advertise all subnet routes.
Follow these steps to configure route automatic summarization:
|
Use the command… |
Remarks |
|
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Enable RIP-2 automatic route summarization |
summary |
Optional Enabled by default |
II. Advertise a summary route
You can configure RIP-2 to advertise a summary route on the specified interface.
To do so, use the following commands:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Disable RIP-2 automatic route summarization |
undo summary |
Required Enabled by default |
|
Exit to system view |
quit |
— |
|
Enter interface view |
interface interface-type interface-number |
— |
|
Configure to advertise a summary route |
rip summary-address ip-address { mask | mask-length } |
Required |
& Note:
You need disable RIP-2 route automatic summarization before advertising a summary route on an interface.
1.3.3 Disabling Host Route Reception
Sometimes a router may receive many host routes from the same network, which are not helpful for routing and occupy a large amount of network resources. In this case, you can disable RIP from receiving host routes to save network resources.
Follow these steps to disable RIP from receiving host routes:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
— |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
— |
|
Disable RIP from receiving host routes |
undo host-route |
Required Enabled by default |
& Note:
RIPv2 can be disabled from receiving host routes, but RIPv1 cannot.
1.3.4 Advertising a Default Route
You can configure RIP to advertise a default route with the specified metric to RIP neighbors.
Follow these steps to configure RIP to advertise a default route:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Enable RIP to advertise a default route |
default-route originate cost value |
Required Not enabled by default |
& Note:
The router enabled to advertise a default route does not receive default routes from RIP neighbors.
1.3.5 Configuring Inbound/Outbound Route Filtering Policies
Route filtering is supported by the router. You can filter routes by configuring the inbound and outbound route filtering policies via referencing an ACL and IP prefix list. You can also specify to receive only routes from a specified neighbor.
Follow these steps to configure a routing policy:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] |
–– |
|
Define a filtering policy for incoming routes |
filter-policy { acl-number | gateway ip-prefix-name | ip-prefix ip-prefix-name [ gateway ip-prefix-name ] } import [ interface-type interface-number ] |
Required By default, no inbound filtering is configured by default. |
|
Define a filtering policy for outgoing routes |
filter-policy { acl-number | ip-prefix ip-prefix-name } export [ protocol [ process-id ] | interface-type interface-number ] |
Required No outbound filtering is configured by default. |
1.3.6 Configuring a Priority for RIP
Multiple IGP protocols may run in a router. If you want RIP routes to have a higher priority than those learned from other routing protocols, you should assign RIP a smaller priority value to influence optimal route selection.
Follow these steps to configure a priority for RIP:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Configure a priority for RIP |
preference [ route-policy route-policy-name ] value |
Optional 100 by default |
1.3.7 Configuring RIP Route Redistribution
Follow these steps to configure RIP route redistribution:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Configure a default metric for redistributed routes |
default cost value |
Optional The default metric is applied if no metric is specified when redistributing routes. The default metric of a redistributed route is 0 by default. |
|
Redistribute routes from another protocol |
import-route protocol [ process-id ] [ allow-ibgp ] [ cost cost | route-policy route-policy-name | tag tag ] * |
Required |
1.4 Optimizing the RIP Network
This section covers the following topics:
l Configuring the Split Horizon and Poison Reverse
l Configuring the Maximum Number of Load Balanced Routes
l Configuring RIP Message Check
l Configuring RIP-2 Message Authentication
l Configuring RIP-to-MIB Binding
Finish the following tasks before configuring the RIP network optimization.
l Configure network addresses on interfaces, and make sure neighboring nodes are reachable
l Configure basic RIP functions.
1.4.1 Configuring RIP Timers
Follow these steps to configure RIP timers:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Configure values for RIP timers |
timers { garbage-collect garbage-collect-value | suppress suppress-value | timeout timeout-value | update update-value }* |
Optional By default, 30s for update timer, 180s for timeout timer, 120s for suppress timer, and 120s for garbage-collect timer |
& Note:
Based on the network performance, you should make RIP timers of RIP routers identical to each other to avoid unnecessary traffic or route oscillation.
1.4.2 Configuring the Split Horizon and Poison Reverse
I. Configure split horizon
The split horizon function disables an interface from sending routes received by the interface itself, so as to prevent routing loops between adjacent routers.
Follow these steps to configure the split horizon function:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
— |
|
Enter interface view |
interface interface-type interface-number |
— |
|
Enable split horizon |
rip split-horizon |
Optional Enabled by default |
& Note:
Disabling the split horizon function on a point-to-point link does not take effect.
II. Configure the poison reverse
The poison reverse function allows an interface to advertise the routes received by itself, but the metric of these routes is set to 16, making them unreachable.
Follow these steps to configure the poise reserve function:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
— |
|
Enter interface view |
interface interface-type interface-number |
— |
|
Enable the poison reverse function |
rip poison-reverse |
Required Disabled by default |
1.4.3 Configuring the Maximum Number of Load Balanced Routes
Follow these steps to configure the maximum number of load balanced routes:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Configure the maximum number of load balanced routes |
maximum load-balancing number |
Optional |
1.4.4 Configuring RIP Message Check
Some fields in the RIP-1 message must be zero. These fields are called zero fields. You can enable the zero field check on received RIP-1 messages. If any such field contains a non-zero value, the RIP-1 message will not be processed. If you are sure that all messages are trusty, you can disable the zero field check to save the CPU processing time.
In addition, you can enable the source IP address validation on received messages. For the message received on an Ethernet interface, RIP compares the source IP address of the message with the IP address of the interface. If they are not in the same network segment, RIP discards the message. For a message received on a serial interface, RIP checks whether the source address of the message is the IP address of the peer interface. If not, RIP discards the message.
Follow these steps to configure RIP message check:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Enable the zero field check on received RIP-1 messages |
checkzero |
Optional Enabled by default |
|
Enable the source IP address validation on received RIP messages |
validate-source-address |
Optional Enabled by default |
& Note:
l The zero field check is invalid for RIP-2 messages.
l The source IP address validation should be disabled when a non direct RIP neighbor exists.
1.4.5 Configuring RIP-2 Message Authentication
RIP-2 supports two authentication modes: plain text and MD5.
In plain text authentication, the authentication information is sent with the RIP message, which cannot meet high security needs.
Follow these steps to configure RIP-2 message authentication:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter interface view |
interface interface-type interface-number |
–– |
|
Configure RIP-2 authentication mode |
rip authentication-mode { md5 { rfc2082 key-string key-id | rfc2453 key-string } | simple password } |
Required |
1.4.6 Configuring a RIP Neighbor
Usually, RIP sends messages to broadcast or multicast addresses. On non broadcast or multicast links, you need to manually specify a RIP neighbor. If the specified neighbor is not directly connected, you must disable the source address check on update messages.
Follow these steps to configure a RIP neighbor:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enter RIP view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
–– |
|
Specify a RIP neighbor |
peer ip-address |
Required |
|
Disable source address check on received RIP update messages |
undo validate-source-address |
Required Not disabled by default |
& Note:
You need not use the peer ip-address command when the neighbor is directly connected; otherwise the neighbor may receive both the unicast and multicast (or broadcast) of the same routing information.
1.4.7 Configuring TRIP
In a connection oriented network, a device may establish connections to multiple remote devices. In a WAN, links are created and removed as needed. In such applications, a link created between two nodes for data transmission is temporary and infrequently.
TRIP should be enabled when it is necessary to exchange routing information via on-demand links or triggered RIP.
I. Enable TRIP
Follow these steps to enable TRIP:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Enable RIP |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
Required |
|
Return to system view |
quit |
–– |
|
Enter interface view |
interface interface-type interface-number |
–– |
|
Enable TRIP |
rip triggered |
Required Disabled by default. |
& Note:
If RIP is disabled, TRIP is also disabled.
II. Configure TRIP retransmission parameters
You can specify intervals and upper limits for Update Request and Response retransmissions as needed.
For two routers on an analog dial-up link, the difference between retransmission intervals on the two ends must be bigger than 50 seconds; otherwise, they can not become TRIP neighbors.
Follow these steps to configure TRIP retransmission parameters:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
— |
|
Enable RIP and enter its view |
rip [ process-id ] [ vpn-instance vpn-instance-name ] |
Required |
|
Configure the interval for retransmitting an Update Request or Update Response |
trip retransmit timer retransmit-time-value |
Required 5 seconds by default |
|
Configure the upper limit for retransmitting an Update Request or Update Response |
trip retransmit count retransmit-count-value |
Optional 36 by default |
& Note:
The maximum retransmission time (upper limit × interval) for a packet cannot be too long lest when its neighbor is down, the router still resends the packet.
1.4.8 Configuring RIP-to-MIB Binding
Follow these steps to bind RIP to MIB:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
–– |
|
Bind RIP to MIB |
rip mib-binding process-id |
Optional By default, MIB is bound to the RIP process with the smallest process ID |
1.5 Displaying and Maintaining RIP Configuration
|
Use the command… |
Remarks |
|
|
Display RIP current status and configuration information |
display rip [ process-id | vpn-instance vpn-instance-name ] |
Available in any view |
|
Display all active routes in RIP database |
display rip process-id database |
|
|
Display RIP interface information |
display rip process-id interface [ interface-type interface-number ] |
|
|
Display routing information about a specified RIP process |
display rip process-id route [ statistics | ip-address { mask | mask-length } | peer ip-address ] |
|
|
Clear the statistics of a RIP process |
reset rip process-id statistics |
Available in user view |
1.6 RIP Configuration Examples
1.6.1 Configuring the RIP Version
I. Network requirements
As shown in Figure 1-4, enable RIP-2 on all interfaces on Switch A and Switch B.
II. Network diagram
Figure 1-4 Network diagram for RIP version configuration
III. Configuration procedure
1) Configure an IP address for each interface (only the IP address configuration for the VLAN interfaces is given in the following examples)
# Configure Switch A.
<SwitchA> system-view
[SwitchA] vlan 100
[SwitchA-vlan100] port ethernet1/1
[SwitchA-vlan100] quit
[SwitchA] interface vlan-interface 100
[SwitchA-Vlan-interface100] ip address 192.168.1 3 24
# Configure Switch B.
<SwitchB> system-view
[SwitchB] vlan 100
[SwitchB-vlan100] port ethernet1/2
[SwitchB-vlan100] quit
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] ip address 192.168.1.2 24
2) Configure basic RIP functions
# Configure Switch A.
[SwitchA] rip
[SwitchA-rip-1] network 192.168.1.0
[SwitchA-rip-1] network 172.16.0.0
[SwitchA-rip-1] network 172.17.0.0
# Configure Switch B.
[SwitchB] rip
[SwitchB-rip-1] network 192.168.1.0
[SwitchB-rip-1] network 10.0.0.0
# Display the RIP routing table of Switch A.
[SwitchA] display rip 1 route
Route Flags: R - RIP, T - TRIP
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
--------------------------------------------------------------------------
Peer 192.168.1.2 on Vlan-interface100
Destination/Mask Nexthop Cost Tag Flags Sec
10.0.0.0/8 192.168.1.2 1 0 RA 11
From the routing table, you can find RIP-1 uses natural mask.
3) Configure RIP version
# Configure RIP-2 on Switch A.
[SwitchA] rip
[SwitchA-rip-1] version 2
[SwitchA-rip-1] undo summary
# Configure RIP-2 on Switch B.
[SwitchB] rip
[SwitchB-rip-1] version 2
[SwitchB-rip-1] undo summary
# Display the RIP routing table on Switch A.
[SwitchA] display rip 1 route
Route Flags: R - RIP, T - TRIP
P - Permanent, A - Aging, S - Suppressed, G - Garbage-collect
----------------------------------------------------------------------------
Peer 192.168.1.2 on Vlan-interface100
Destination/Mask Nexthop Cost Tag Flags Sec
10.0.0.0/8 192.168.1.2 1 0 RA 50
10.2.1.0/24 192.168.1.2 1 0 RA 16
10.1.1.0/24 192.168.1.2 1 0 RA 16
From the routing table, you can see RIP-2 uses classless subnet mask.
& Note:
Since RIP-1 routing information has a long aging time, it will still exist until aged out after RIP-2 is configured.
1.6.2 Configuring RIP Route Redistribution
I. Network requirements
As shown in Figure 1-5, two RIP processes are running on Switch B, which communicates with Switch A through RIP100 and with Switch C through RIP 200.
Configure route redistribution on Switch B, letting the two RIP processes redistribute routes from each other. Set the cost of redistributed routes from RIP 200 to 3. Configure a filtering policy on Switch B to filter out the route 192.168.4.0/24 from RIP200, making the route not advertised to Switch A.
II. Network diagram
Figure 1-5 Network diagram for RIP route redistribution configuration
III. Configuration procedure
1) Configure an IP address for each interface (Omitted).
2) Configure basic RIP functions.
# Enable RIP 100 on Switch A.
<SwitchA> system-view
[SwitchA] rip 100
[SwitchA-rip-100] network 192.168.0.0
[SwitchA-rip-100] network 192.168.1.0
# Enable RIP 100 and RIP 200 on Switch B.
<SwitchB> system-view
[SwitchB] rip 100
[SwitchB-rip-100] network 192.168.1.0
[SwitchB-rip-100] quit
[SwitchB] rip 200
[SwitchB-rip-200] network 192.168.2.0
[SwitchB-rip-200] quit
# Enable RIP 200 on Switch C.
<SwitchC> system-view
[SwitchC] rip 200
[SwitchC-rip-200] network 192.168.2.0
[SwitchC-rip-200] network 192.168.3.0
[SwitchC-rip-200] network 192.168.4.0
# Display the routing table of Switch A.
[SwitchA] display ip routing-table
Routing Tables: Public
Destinations : 10 Routes : 10
Destination/Mask Proto Pre Cost NextHop Interface
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
172.16.1.0/24 Direct 0 0 172.16.1.1 Eth1/3
172.16.1.1/32 Direct 0 0 127.0.0.1 InLoop0
172.17.1.0/24 Direct 0 0 172.17.1.1 Eth1/2
172.17.1.1/32 Direct 0 0 127.0.0.1 InLoop0
192.168.1.0/24 Direct 0 0 192.168.1.3 Vlan100
192.168.1.3/32 Direct 0 0 127.0.0.1 InLoop0
192.168.0.0/24 Direct 0 0 192.168.0.1 Vlan101
192.168.0.1/32 Direct 0 0 127.0.0.1 InLoop0
3) Configure route redistribution
# Configure route redistribution between the two RIP processes on Switch B.
[SwitchB] rip 100
[SwitchB-rip-100] default cost 3
[SwitchB-rip-100] import-route rip 200
[SwitchB-rip-100] quit
[SwitchB] rip 200
[SwitchB-rip-200] import-route rip 100
[SwitchB-rip-200] quit
# Display the routing table of Switch A.
[SwitchA] display ip routing-table
Routing Tables: Public
Destinations : 12 Routes : 12
Destination/Mask Proto Pre Cost NextHop Interface
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
172.16.1.0/24 Direct 0 0 172.16.1.1 Eth1/3
172.16.1.1/32 Direct 0 0 127.0.0.1 InLoop0
172.17.1.0/24 Direct 0 0 172.17.1.1 Eth1/2
172.17.1.1/32 Direct 0 0 127.0.0.1 InLoop0
192.168.1.0/24 Direct 0 0 192.168.1.3 Vlan100
192.168.1.3/32 Direct 0 0 127.0.0.1 InLoop0
192.168.0.0/24 Direct 0 0 192.168.0.1 Vlan101
192.168.0.1/32 Direct 0 0 127.0.0.1 InLoop0
192.168.3.0/24 RIP 100 4 192.168.1.2 Vlan100
192.168.4.0/24 RIP 100 4 192.168.1.2 Vlan100
4) Configure an filtering policy to filter redistributed routes
# Define ACL2000 and reference it to a filtering policy to filter routes redistributed from RIP 200 on Switch B.
[SwitchB] acl number 2000
[SwitchB-acl-basic-2000] rule deny source 192.168.4.0 0.0.0.255
[SwitchB-acl-basic-2000] rule permit
[SwitchB-acl-basic-2000] quit
[SwitchB] rip 100
[SwitchB-rip-100] filter-policy 2000 export rip 200
# Display the routing table of Switch A.
[SwitchA] display ip routing-table
Routing Tables: Public
Destinations : 11 Routes : 11
Destination/Mask Proto Pre Cost NextHop Interface
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
172.16.1.0/24 Direct 0 0 172.16.1.1 Eth1/3
172.16.1.1/32 Direct 0 0 127.0.0.1 InLoop0
172.17.1.0/24 Direct 0 0 172.17.1.1 Eth1/2
172.17.1.1/32 Direct 0 0 127.0.0.1 InLoop0
192.168.1.0/24 Direct 0 0 192.168.1.3 Vlan100
192.168.1.3/32 Direct 0 0 127.0.0.1 InLoop0
192.168.0.0/24 Direct 0 0 192.168.0.1 Vlan101
192.168.0.1/32 Direct 0 0 127.0.0.1 InLoop0
192.168.3.0/24 RIP 100 4 192.168.1.2 Vlan100
1.7 Troubleshooting RIP Configuration
1.7.1 No RIP Updates Received
Symptom:
No RIP updates are received when the links work well.
Analysis:
After enabling RIP, you must use the network command to enable corresponding interfaces. Make sure no interfaces are disabled from handling RIP messages.
If the peer is configured to send multicast messages, the same should be configured on the local end.
Solution:
l Use the display current-configuration command to check RIP configuration
l Use the display rip command to check whether some interface is disabled
1.7.2 Route Oscillation Occurred
Symptom:
When all links work well, route oscillation occurs on the RIP network. After displaying the routing table, you may find some routes appear and disappear in the routing table intermittently.
Analysis:
In the RIP network, make sure all the same timers within the whole network are identical and relationships between timers are reasonable. For example, the timeout timer value should be larger than the update timer value.
Solution:
l Use the display rip command to check the configuration of RIP timers
l Use the timers command to adjust timers properly.
