H3C BGP Configuration Examples

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Software version: Release 7951P01

Document version: 6W100-20200625

 

Except for the trademarks of New H3C Technologies Co., Ltd., any trademarks that may be mentioned in this document are the property of their respective owners.

The information in this document is subject to change without notice.

 

Contents

Introduction· 1

Prerequisites· 1

Example: Configuring basic BGP·· 1

Network configuration· 1

Analysis· 1

Restrictions and guidelines· 1

Procedures· 2

Verifying the configuration· 5

Configuration files· 6

Examples: Configuring BGP and IGP route redistribution· 7

Network configuration· 7

Analysis· 7

Restrictions and guidelines· 8

Procedures· 8

Verifying the configuration· 10

Configuration files· 11

Related documentation· 12

 

Introduction

This document provides BGP configuration examples.

Prerequisites

The configuration examples in this document were created and verified in a lab environment, and all the devices were started with the factory default configuration. When you are working on a live network, make sure you understand the potential impact of every command on your network.

This document assumes that you have basic knowledge of BGP.

Example: Configuring basic BGP

Network configuration

As shown in Figure 1, all routers run BGP. Run EBGP between Router A and Router B, and run IBGP between Router B and Router C so that Router C can access the network 8.1.1.0/24 connected to Router A.

Figure 1 Network diagram

 

Analysis

To enable Router B to communicate with Router C through loopback interfaces, enable OSPF in AS 65009.

By default, BGP does not advertise local networks. To enable Router C to access the network 8.1.1.0/24 connected directly to Router A, perform the following tasks:

·     Add network 8.1.1.0/24 to the BGP routing table of Router A.

·     Add networks 3.1.1.0/24 and 9.1.1.0/24 to the BGP routing table of Router B.

Restrictions and guidelines

When you configure basic BGP, follow these restrictions and guidelines:

·     Use loopback interfaces to establish IBGP connections to prevent route flapping caused by port state changes.

·     Loopback interfaces are virtual interfaces. Use the peer connect-interface command to specify the loopback interface as the source interface for establishing BGP connections.

·     The EBGP peers, Router A and Router B, are located in different ASs. Typically, their loopback interfaces are not reachable to each other, so the routers use directly connected interfaces to establish EBGP sessions.

Procedures

1.     Configure IP addresses for interfaces:

# Configure an IP address for GigabitEthernet 3/1/1.

<RouterA> system-view

[RouterA] interface GigabitEthernet 3/1/1

[RouterA-GigabitEthernet3/1/1] ip address 8.1.1.1 24

# Configure IP addresses for other interfaces in the same way that GigabitEthernet 3/1/1 is configured. (Details not shown.)

2.     Configure IBGP:

# Configure Router B.

<RouterB> system-view

[RouterB] bgp 65009

[RouterB-bgp-default] router-id 2.2.2.2

[RouterB-bgp-default] peer 3.3.3.3 as-number 65009

[RouterB-bgp-default] peer 3.3.3.3 connect-interface Loopback 0

[RouterB-bgp-default] address-family ipv4 unicast

[RouterB-bgp-default-ipv4] peer 3.3.3.3 enable

[RouterB-bgp-default-ipv4] quit

[RouterB-bgp-default] quit

[RouterB] ospf 1

[RouterB-ospf-1] area 0

[RouterB-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0

[RouterB-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255

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

[RouterB-ospf-1] quit

# Configure Router C.

<RouterC> system-view

[RouterC] bgp 65009

[RouterC-bgp-default] router-id 3.3.3.3

[RouterC-bgp-default] peer 2.2.2.2 as-number 65009

[RouterC-bgp-default] peer 2.2.2.2 connect-interface Loopback 0

[RouterC-bgp-default] address-family ipv4 unicast

[RouterC-bgp-default-ipv4] peer 2.2.2.2 enable

[RouterC-bgp-default-ipv4] quit

[RouterC-bgp-default] quit

[RouterC] ospf 1

[RouterC-ospf-1] area 0

[RouterC-ospf-1-area-0.0.0.0] network 3.3.3.3 0.0.0.0

[RouterC-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255

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

[RouterC-ospf-1] quit

# Display BGP peer information on Router C.

[RouterC] display bgp peer ipv4

 

 BGP local router ID : 3.3.3.3

 Local AS number : 65009

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

 

Peer                    AS  MsgRcvd  MsgSent OutQ PrefRcv Up/Down  State

 

  2.2.2.2              65009        2        2    0       0 00:00:13 Established

The output shows that Router C has established an IBGP peer relationship with Router B.

3.     Configure EBGP:

# Configure Router A.

<RouterA> system-view

[RouterA] bgp 65008

[RouterA-bgp-default] router-id 1.1.1.1

[RouterA-bgp-default] peer 3.1.1.1 as-number 65009

[RouterA-bgp-default] address-family ipv4 unicast

[RouterA-bgp-default-ipv4] peer 3.1.1.1 enable

[RouterA-bgp-default-ipv4] network 8.1.1.0 24

[RouterA-bgp-default-ipv4] quit

[RouterA-bgp-default] quit

# Configure Router B.

[RouterB] bgp 65009

[RouterB-bgp-default] peer 3.1.1.2 as-number 65008

[RouterB-bgp-default] address-family ipv4 unicast

[RouterB-bgp-default-ipv4] peer 3.1.1.2 enable

[RouterB-bgp-default-ipv4] quit

[RouterB-bgp-default] quit

# Display BGP peer information on Router B.

[RouterB] display bgp peer ipv4

 

 BGP local router ID : 2.2.2.2

 Local AS number : 65009

 Total number of peers : 2                 Peers in established state : 2

 

  Peer                    AS  MsgRcvd  MsgSent OutQ PrefRcv Up/Down  State

 

  3.3.3.3              65009        4        4    0       0 00:02:49 Established

  3.1.1.2              65008        2        2    0       0 00:00:05 Established

The output shows that Router B has established an IBGP peer relationship with Router C and an EBGP peer relationship with Router A.

# Display the BGP routing table on Router A.

[RouterA] display bgp routing-table ipv4

 

 Total number of routes: 1

 

 BGP local router ID is 1.1.1.1

 Status codes: * - valid, > - best, d - dampened, h - history

               s - suppressed, S - stale, i - internal, e – external

               a - additional-path

       Origin: i - IGP, e - EGP, ? – incomplete

 

     Network            NextHop         MED        LocPrf     PrefVal Path/Ogn

 

* >  8.1.1.0/24         8.1.1.1         0                     32768   i

# Display the BGP routing table on Router B.

[RouterB] display bgp routing-table ipv4

 

 Total number of routes: 1

 

 BGP local router ID is 2.2.2.2

 Status codes: * - valid, > - best, d - dampened, h - history

               s - suppressed, S - stale, i - internal, e – external

               a - additional-path

       Origin: i - IGP, e - EGP, ? - incomplete

 

     Network            NextHop         MED        LocPrf     PrefVal Path/Ogn

 

* >e 8.1.1.0/24         3.1.1.2         0                     0       65008i

# Display the BGP routing table on Router C.

[RouterC] display bgp routing-table ipv4

 

 Total number of routes: 1

 

 BGP local router ID is 3.3.3.3

 Status codes: * - valid, > - best, d - dampened, h – history

               s - suppressed, S - stale, i - internal, e – external

               a - additional-path

       Origin: i - IGP, e - EGP, ? - incomplete

 

     Network            NextHop         MED        LocPrf     PrefVal Path/Ogn

 

   i 8.1.1.0/24         3.1.1.2         0          100        0       65008i

The outputs show that Router A has learned no route to AS 65009, and Router C has learned network 8.1.1.0, but the next hop 3.1.1.2 is unreachable. As a result, the route is invalid.

4.     Configure BGP to redistribute direct routes on Router B:

# Configure Router B.

[RouterB] bgp 65009

[RouterB-bgp-default] address-family ipv4 unicast

[RouterB-bgp-default-ipv4] network 3.1.1.0 24

[RouterB-bgp-default-ipv4] network 9.1.1.0 24

[RouterB-bgp-default-ipv4] quit

[RouterB-bgp-default] quit

# Display the BGP routing table on Router A.

[RouterA] display bgp routing-table ipv4

 

 Total number of routes: 3

 

 BGP local router ID is 1.1.1.1

 Status codes: * - valid, > - best, d - dampened, h - history

               s - suppressed, S - stale, i - internal, e – external

               a - additional-path

       Origin: i - IGP, e - EGP, ? - incomplete

 

     Network            NextHop         MED        LocPrf     PrefVal Path/Ogn

 

* >e 3.1.1.0/24         3.1.1.1         0                     0       65009?

* >  8.1.1.0/24         8.1.1.1         0                     32768   i

* >e 9.1.1.0/24         3.1.1.1         0                     0       65009i

The output shows that route 9.1.1.0/24 has been added in Router A's routing table.

# Display the BGP routing table on Router C.

[RouterC] display bgp routing-table ipv4

 

 Total number of routes: 3

 

 BGP local router ID is 3.3.3.3

 Status codes: * - valid, > - best, d - dampened, h - history

               s - suppressed, S - stale, i - internal, e – external

               a - additional-path

       Origin: i - IGP, e - EGP, ? - incomplete

 

     Network            NextHop         MED        LocPrf     PrefVal Path/Ogn

 

* >i 3.1.1.0/24         2.2.2.2         0          100        0       ?

* >i 8.1.1.0/24         3.1.1.2         0          100        0       65008i

* >i 9.1.1.0/24         2.2.2.2         0          100        0       i

The output shows that the route 8.1.1.0 becomes valid with the next hop as Router A.

Verifying the configuration

# Verify that Router C can ping 8.1.1.1.

[RouterC] ping 8.1.1.1

Ping 8.1.1.1 (8.1.1.1): 56 data bytes, press CTRL_C to break

56 bytes from 8.1.1.1: icmp_seq=0 ttl=254 time=10.000 ms

56 bytes from 8.1.1.1: icmp_seq=1 ttl=254 time=4.000 ms

56 bytes from 8.1.1.1: icmp_seq=2 ttl=254 time=4.000 ms

56 bytes from 8.1.1.1: icmp_seq=3 ttl=254 time=3.000 ms

56 bytes from 8.1.1.1: icmp_seq=4 ttl=254 time=3.000 ms

 

--- Ping statistics for 8.1.1.1 ---

5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss

round-trip min/avg/max/std-dev = 3.000/4.800/10.000/2.638 ms

Configuration files

·     Router A:

#

interface Loopback0

 ip address 1.1.1.1 255.255.255.255

#

interface GigabitEthernet 3/1/1

 ip address 8.1.1.1 255.255.255.0

#

interface GigabitEthernet 3/1/2

 ip address 3.1.1.2 255.255.255.0

#

bgp 65008

 router-id 1.1.1.1

 peer 3.1.1.1 as-number 65009

#

address-family ipv4 unicast

 network 8.1.1.0 255.255.255.0

 peer 3.1.1.1 enable

#

·     Router B:

#

interface Loopback0

 ip address 2.2.2.2 255.255.255.255

#

interface GigabitEthernet 3/1/1

 ip address 3.1.1.1 255.255.255.0

#

interface GigabitEthernet 3/1/2

 ip address 9.1.1.1 255.255.255.0

#

bgp 65009

 router-id 2.2.2.2

 peer 3.1.1.2 as-number 65008

 peer 3.3.3.3 as-number 65009

 peer 3.3.3.3 connect-interface Loopback0

#

address-family ipv4 unicast

 network 3.1.1.0 24

 network 9.1.1.0 24

 peer 3.1.1.2 enable

 peer 3.3.3.3 enable

#

ospf 1

 area 0.0.0.0

  network 2.2.2.2 0.0.0.0

  network 9.1.1.0 0.0.0.255

#

·     Router C:

#

interface Loopback0

 ip address 3.3.3.3 255.255.255.255

#

interface GigabitEthernet 3/1/1

 ip address 9.1.1.2 255.255.255.0

#

bgp 65009

 router-id 3.3.3.3

 peer 2.2.2.2 as-number 65009

 peer 2.2.2.2 connect-interface Loopback0

#

address-family ipv4 unicast

 peer 2.2.2.2 enable

#

ospf 1

 area 0.0.0.0

  network 3.3.3.3 0.0.0.0

  network 9.1.1.0 0.0.0.255

#

Examples: Configuring BGP and IGP route redistribution

Network configuration

As shown in Figure 2, all devices of company A belong to AS 65008 and all devices of company B belong to AS 65009. Run EBGP between Router A and Router B, and run OSPF between Router B and Router C to allow communication only between networks 9.1.2.0/24 and 8.1.1.0/24.

Figure 2 Network diagram

 

Analysis

To enable Router A to obtain the route to 9.1.2.0/24, configure BGP to redistribute routes from OSPF on Router B. To enable Router C to obtain the route to 8.1.1.0/24, configure OSPF to redistribute routes from BGP on Router B.

Restrictions and guidelines

The EBGP peers, Router A and Router B, are located in different ASs. Typically, their loopback interfaces are not reachable to each other, so the routers use directly connected interfaces to establish EBGP sessions.

Procedures

1.     Configure IP addresses for interfaces:

# Configure an IP address for GigabitEthernet 3/1/1.

<RouterA> system-view

[RouterA] interface GigabitEthernet 3/1/1

[RouterA-GigabitEthernet3/1/1] ip address 8.1.1.1 255.255.255.0

# Configure IP addresses for other interfaces in the same way that GigabitEthernet 3/1/1 is configured. (Details not shown.)

2.     Enable OSPF in AS 65009:

# Configure Router B.

<RouterB> system-view

[RouterB] ospf 1

[RouterB-ospf-1] area 0

[RouterB-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0

[RouterB-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255

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

[RouterB-ospf-1] quit

# Configure Router C.

<RouterC> system-view

[RouterC] ospf 1

[RouterC-ospf-1] area 0

[RouterC-ospf-1-area-0.0.0.0] network 9.1.1.0 0.0.0.255

[RouterC-ospf-1-area-0.0.0.0] network 9.1.2.0 0.0.0.255

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

[RouterC-ospf-1] quit

3.     Configure the EBGP connection and add network 8.1.1.0/24 to the BGP routing table of Router A:

# Configure Router A.

<RouterA> system-view

[RouterA] bgp 65008

[RouterA-bgp-default] router-id 1.1.1.1

[RouterA-bgp-default] peer 3.1.1.1 as-number 65009

[RouterA-bgp-default] address-family ipv4 unicast

[RouterA-bgp-default-ipv4] peer 3.1.1.1 enable

[RouterA-bgp-default-ipv4] network 8.1.1.0 24

[RouterA-bgp-default-ipv4] quit

[RouterA-bgp-default] quit

# Configure Router B.

[RouterB] bgp 65009

[RouterB-bgp-default] router-id 2.2.2.2

[RouterB-bgp-default] peer 3.1.1.2 as-number 65008

[RouterB-bgp-default] address-family ipv4 unicast

[RouterB-bgp-default-ipv4] peer 3.1.1.2 enable

4.     Configure BGP and IGP route redistribution:

# Configure route redistribution between BGP and OSPF on Router B.

[RouterB-bgp-default-ipv4] import-route ospf 1

[RouterB-bgp-default-ipv4] quit

[RouterB-bgp-default] quit

[RouterB] ospf 1

[RouterB-ospf-1] import-route bgp

[RouterB-ospf-1] quit

# Display the BGP routing table on Router A.

[RouterA] display bgp routing-table ipv4

 

 Total number of routes: 3

 

 BGP local router ID is 1.1.1.1

 Status codes: * - valid, > - best, d - dampened, h - history

               s - suppressed, S - stale, i - internal, e – external

               a - additional-path

       Origin: i - IGP, e - EGP, ? - incomplete

 

     Network            NextHop         MED        LocPrf     PrefVal Path/Ogn

 

* >  8.1.1.0/24         8.1.1.1         0                     32768   i

* >e 9.1.2.0/24         3.1.1.1         1                     0       65009?

The output shows that Router A has obtained the route to 9.1.2.0/24.

# Display the OSPF routing table on Router C.

[RouterC] display ospf routing

 

          OSPF Process 1 with Router ID 3.3.3.3

                   Routing Table

 

                Topology base (MTID 0)

 

 Routing for Network

 Destination        Cost     Type    NextHop         AdvRouter       Area

 9.1.1.0/24         1        Transit 9.1.1.2         3.3.3.3         0.0.0.0

9.1.2.0/24         1        Stub    9.1.2.1         192.168.0.63    0.0.0.0

 2.2.2.2/32         1        Stub    9.1.1.1         2.2.2.2         0.0.0.0

 

 Routing for ASEs

 Destination        Cost     Type    Tag         NextHop         AdvRouter

 8.1.1.0/24         1        Type2   1           9.1.1.1         2.2.2.2

 

 Total Nets: 3

 Intra Area: 2  Inter Area: 0  ASE: 1  NSSA: 0

The output shows that Router C has obtained the route to 8.1.1.0/24.

Verifying the configuration

# Verify that 8.1.1.1 can ping 9.1.2.1.

[RouterA] ping -a 8.1.1.1 9.1.2.1

Ping 9.1.2.1 (9.1.2.1) from 8.1.1.1: 56 data bytes, press CTRL_C to break

56 bytes from 9.1.2.1: icmp_seq=0 ttl=254 time=10.000 ms

56 bytes from 9.1.2.1: icmp_seq=1 ttl=254 time=12.000 ms

56 bytes from 9.1.2.1: icmp_seq=2 ttl=254 time=2.000 ms

56 bytes from 9.1.2.1: icmp_seq=3 ttl=254 time=7.000 ms

56 bytes from 9.1.2.1: icmp_seq=4 ttl=254 time=9.000 ms

 

--- Ping statistics for 9.1.2.1 ---

5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss

round-trip min/avg/max/std-dev = 2.000/8.000/12.000/3.406 ms

# Verify that 9.1.2.1 can ping 8.1.1.1.

[RouterC] ping -a 9.1.2.1 8.1.1.1

Ping 8.1.1.1 (8.1.1.1) from 9.1.2.1: 56 data bytes, press CTRL_C to break

56 bytes from 8.1.1.1: icmp_seq=0 ttl=254 time=9.000 ms

56 bytes from 8.1.1.1: icmp_seq=1 ttl=254 time=4.000 ms

56 bytes from 8.1.1.1: icmp_seq=2 ttl=254 time=3.000 ms

56 bytes from 8.1.1.1: icmp_seq=3 ttl=254 time=3.000 ms

56 bytes from 8.1.1.1: icmp_seq=4 ttl=254 time=3.000 ms

 

--- Ping statistics for 8.1.1.1 ---

5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss

round-trip min/avg/max/std-dev = 3.000/4.400/9.000/2.332 ms

# Verify that 8.1.2.1 cannot ping 9.1.2.1 or 9.1.3.1.

[RouterA] ping –a 8.1.2.1 9.1.2.1

Ping 9.1.2.1 (9.1.2.1) from 8.1.2.1: 56 data bytes, press CTRL_C to break

Request time out

Request time out

Request time out

Request time out

Request time out

 

--- Ping statistics for 9.1.2.1 ---

5 packet(s) transmitted, 0 packet(s) received, 100.0% packet loss

 

[RouterA] ping –a 8.1.2.1 9.1.3.1

Ping 9.1.3.1 (9.1.3.1) from 8.1.2.1: 56 data bytes, press CTRL_C to break

Request time out

Request time out

Request time out

Request time out

Request time out

 

--- Ping statistics for 9.1.3.1 ---

5 packet(s) transmitted, 0 packet(s) received, 100.0% packet loss

# Verify that 9.1.3.1 cannot ping 8.1.1.1 or 8.1.2.1.

[RouterC] ping –a 9.1.3.1 8.1.1.1

Ping 8.1.1.1 (8.1.1.1) from 9.1.3.1: 56 data bytes, press CTRL_C to break

Request time out

Request time out

Request time out

Request time out

Request time out

 

--- Ping statistics for 8.1.1.1 ---

5 packet(s) transmitted, 0 packet(s) received, 100.0% packet loss

 

[RouterC] ping –a 9.1.3.1 8.1.2.1

Ping 8.1.2.1 (8.1.2.1) from 9.1.3.1: 56 data bytes, press CTRL_C to break

Request time out

Request time out

Request time out

Request time out

Request time out

 

--- Ping statistics for 8.1.2.1 ---

5 packet(s) transmitted, 0 packet(s) received, 100.0% packet loss

Configuration files

·     Router A:

#

interface Loopback0

 ip address 1.1.1.1 255.255.255.255

#

interface GigabitEthernet 3/1/1

 ip address 8.1.1.1 255.255.255.0

#

interface GigabitEthernet 3/1/2

 ip address 3.1.1.2 255.255.255.0

#

interface GigabitEthernet 3/1/3

 ip address 8.1.2.1 255.255.255.0

#

bgp 65008

 router-id 1.1.1.1

 peer 3.1.1.1 as-number 65009

#

address-family ipv4 unicast

 network 8.1.1.0 255.255.255.0

 peer 3.1.1.1 enable

#

·     Router B:

#

interface Loopback0

 ip address 2.2.2.2 255.255.255.255

#

interface GigabitEthernet 3/1/1

ip address 3.1.1.1 255.255.255.0

#

interface GigabitEthernet 3/1/2

ip address 9.1.1.1 255.255.255.0

#

bgp 65009

 router-id 2.2.2.2

 peer 3.1.1.2 as-number 65008

#

address-family ipv4 unicast

 import-route ospf 1

 peer 3.1.1.2 enable

#

ospf 1

 import-route bgp

 area 0.0.0.0

  network 2.2.2.2 0.0.0.0

  network 9.1.1.0 0.0.0.255

#

·     Router C:

#

interface Loopback0

 ip address 3.3.3.3 255.255.255.255

#

interface GigabitEthernet 3/1/1

 ip address 9.1.1.2 255.255.255.0

#

interface GigabitEthernet 3/1/2

 ip address 9.1.2.1 255.255.255.0

#

interface GigabitEthernet 3/1/3

ip address 9.1.3.1 255.255.255.0

#

ospf 1

 area 0.0.0.0

  network 9.1.1.0 0.0.0.255

  network 9.1.2.0 0.0.0.255

#

Related documentation

·     H3C CR16000-F Routers Layer 3—IP Routing Configuration Guide-Release 7951P01

·     H3C CR16000-F Routers Layer 3—IP Routing Command Reference-Release 7951P01