Configuration on MP-eBGP

Introduction

This document provides information how to configure multiprotocol extended Border Gateway Protocol (MP-EBGP) in Cisco IOS routers. MP-BGP is an extended BGP that allows BGP to carry routing information for multiple network layer protocols IPv6, VPNv4, and others. MP-BGP allows you to have a unicast routing topology different from a multicast routing topology, which helps to control the network and resources.

Components Used

This document is not restricted to specific software and hardware versions.

The configurations in this document are based on the Cisco 3700 series router that runs Cisco IOS® Software Release 12.4 (15)T 13.

Configure

In this example, the R1 and R3 routers are configured to be in AS 5500 forming iBGP. The R2 router is configured to be in AS 6500. The R1 and R2 routers communicate with each other using MP-EBGP. All the routers are configured with loopback addresses.

Network Diagram

This document uses this network setup:

Configurations

Router R1

R1#show run
Building configuration...
!
version 12.4
!
hostname R1
!
ip cef
!
!
interface Loopback0
 ip address 10.10.10.10 255.255.255.0
!
interface FastEthernet0/0
 ip address 192.168.100.10 255.255.255.0
 duplex auto
 speed auto
!
interface Serial0/0
 ip address 172.16.10.1 255.255.255.0
 mpls ip
 clock rate 2000000
!
router bgp 5500
 no synchronization
 bgp router-id 10.10.10.10
 bgp log-neighbor-changes
 network 192.168.100.0
 redistribute connected
 neighbor 172.16.10.2 remote-as 6500
 neighbor 172.16.10.2 soft-reconfiguration inbound
 neighbor 192.168.100.11 remote-as 5500
 no auto-summary
 !
 address-family vpnv4
  neighbor 172.16.10.2 activate
  neighbor 172.16.10.2 send-community both

!--- Sends the community attribute to a BGP neighbor.

 exit-address-family
!
!
end

Router R2

R2#show run
Building configuration...
!
version 12.4
!
hostname R2
!
ip cef
!
ip vrf WAN
 rd 2020:1
 route-target export 2020:1
 route-target import 2020:1
!
!

interface Loopback0
 ip vrf forwarding WAN

!--- Associates a VRF instance with an interface or subinterface.

 ip address 20.20.20.20 255.255.255.255
!
interface Serial0/0
 ip vrf forwarding WAN
 ip address 172.16.10.2 255.255.255.0
 mpls ip
 clock rate 2000000
!
router bgp 6500
 no synchronization
 bgp router-id 20.20.20.20
 bgp log-neighbor-changes
 neighbor 172.16.10.1 remote-as 5500
 no auto-summary
 !
 !
 address-family vpnv4
  neighbor 172.16.10.1 activate
  neighbor 172.16.10.1 send-community both
 exit-address-family
 !
 address-family ipv4 vrf WAN
  redistribute connected
  redistribute static
  neighbor 172.16.10.1 remote-as 5500
  neighbor 172.16.10.1 activate
  no synchronization
 exit-address-family
!
!
!
end

Router R3
R3#show run
Building configuration...
!
version 12.4
!
hostname R3
!
ip cef
!
!
!
interface Loopback0
 ip address 11.11.11.11 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.100.11 255.255.255.0
 duplex auto
 speed auto
!
router bgp 5500
 no synchronization
 bgp router-id 11.11.11.11
 bgp log-neighbor-changes
 neighbor 192.168.100.10 remote-as 5500
 no auto-summary
!
end

Verify

In order to display entries in the (BGP) routing table, use the show ip bgp command.

In router R2, use the show ip bgp vpnv4 command to display (VPNv4) address information from the (BGP) table.
MP-EBGP is established between the R1 and R2 routers. Use the ping command to verify the reachability from R1 to R2 and vice versa.