R1===================================================================================
hostname R1
ip cef
interface Loopback0
ip address 1.1.1.1 255.255.255.0
!
interface FastEthernet0/0
ip address 12.1.1.1 255.255.255.0
!
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
network 0.0.0.0 255.255.255.255 area 0
R2===================================================================================
hostname R2
no ip domain lookup
!
ip vrf R1_R2
rd 234:2
route-target export 234:2
route-target import 234:4
!
ip cef
ip audit po max-events 100
mpls label range 200 299
mpls label protocol ldp
tag-switching tdp router-id Loopback0
!
interface Loopback0
ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
ip address 23.1.1.2 255.255.255.0
tag-switching ip
!
interface FastEthernet0/1
ip vrf forwarding R1_R2
ip address 12.1.1.2 255.255.255.0
!
router ospf 110
router-id 2.2.2.2
log-adjacency-changes
network 2.2.2.2 0.0.0.0 area 0
network 23.1.1.2 0.0.0.0 area 0
!
router ospf 1 vrf R1_R2
log-adjacency-changes
redistribute bgp 234 subnets
network 12.1.1.2 0.0.0.0 area 0
!
router bgp 234
no bgp default ipv4-unicast
bgp log-neighbor-changes
neighbor 4.4.4.4 remote-as 234
neighbor 4.4.4.4 update-source Loopback0
!
address-family ***v4
neighbor 4.4.4.4 activate
neighbor 4.4.4.4 send-community extended
exit-address-family
!
address-family ipv4 vrf R1_R2
redistribute ospf 1 match internal external 1 external 2
no auto-summary
no synchronization
exit-address-family
R3=====================================================================================
hostname R3
no ip domain lookup
ip cef
mpls label range 300 399
mpls label protocol ldp
tag-switching tdp router-id Loopback0
interface Loopback0
ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
ip address 34.1.1.3 255.255.255.0
duplex auto
speed auto
tag-switching ip
!
interface FastEthernet0/1
ip address 23.1.1.3 255.255.255.0
tag-switching ip
!
router ospf 110
router-id 3.3.3.3
log-adjacency-changes
network 3.3.3.3 0.0.0.0 area 0
network 23.1.1.3 0.0.0.0 area 0
network 34.1.1.3 0.0.0.0 area 0
R4===============================================================================
hostname R4
!
no ip domain lookup
!
ip vrf R4_R5
rd 234:4
route-target export 234:4
route-target import 234:2
!
ip cef
ip audit po max-events 100
mpls label range 400 499
mpls label protocol ldp
tag-switching tdp router-id Loopback0
interface Loopback0
ip address 4.4.4.4 255.255.255.255
!
interface FastEthernet0/0
ip vrf forwarding R4_R5
ip address 45.1.1.4 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 34.1.1.4 255.255.255.0
duplex auto
speed auto
tag-switching ip
!
router ospf 110
router-id 4.4.4.4
log-adjacency-changes
network 4.4.4.4 0.0.0.0 area 0
network 34.1.1.4 0.0.0.0 area 0
!
router ospf 1 vrf R4_R5
log-adjacency-changes
redistribute bgp 234 subnets
network 45.1.1.4 0.0.0.0 area 0
!
router bgp 234
no bgp default ipv4-unicast
bgp log-neighbor-changes
neighbor 2.2.2.2 remote-as 234
neighbor 2.2.2.2 update-source Loopback0
!
address-family ipv4
neighbor 2.2.2.2 activate
no auto-summary
no synchronization
exit-address-family
!
address-family ***v4
neighbor 2.2.2.2 activate
neighbor 2.2.2.2 send-community extended
exit-address-family
!
address-family ipv4 vrf R4_R5
redistribute ospf 1 match internal external 1 external 2
no auto-summary
no synchronization
exit-address-family
R5=================================================================================
hostname R5
ip cef
interface Loopback0
ip address 5.5.5.5 255.255.255.0
!
interface FastEthernet0/1
ip address 45.1.1.5 255.255.255.0
!
router ospf 1
log-adjacency-changes
network 5.5.5.5 0.0.0.0 area 0
network 45.1.1.5 0.0.0.0 area 0
注:R2和R4建立IBGP的邻接关系
若R2与R3建立IBGP，R3与R4建立IBGP，则R3应作为RR，配置如下 R2===================================================================== router bgp 234 no bgp default ipv4-unicast bgp log-neighbor-changes neighbor 3.3.3.3 remote-as 234 neighbor 3.3.3.3 update-source Loopback0 ! address-family ***v4 neighbor 3.3.3.3 activate neighbor 3.3.3.3 send-community extended R3===================================================================== router bgp 234 no bgp default ipv4-unicast bgp log-neighbor-changes neighbor 2.2.2.2 remote-as 234 neighbor 2.2.2.2 update-source Loopback0 neighbor 4.4.4.4 remote-as 234 neighbor 4.4.4.4 update-source Loopback0 ! address-family ***v4 neighbor 2.2.2.2 activate neighbor 2.2.2.2 route-reflector-client neighbor 2.2.2.2 send-community extended neighbor 4.4.4.4 activate neighbor 4.4.4.4 route-reflector-client neighbor 4.4.4.4 send-community extended R4====================================================================== router bgp 234 no bgp default ipv4-unicast bgp log-neighbor-changes neighbor 3.3.3.3 remote-as 234 neighbor 3.3.3.3 update-source Loopback0 ! address-family ipv4 neighbor 2.2.2.2 activate no auto-summary no synchronization exit-address-family ! address-family ***v4 neighbor 3.3.3.3 activate neighbor 3.3.3.3 send-community extended