The document describes a MPLS VPN solution that provides different paths for each VRF using MP-EBGP between route reflectors and PE routers. Route targets and VRF definitions are configured to separate routing tables. MP-EBGP with a different AS is used between PEs to influence path selection and allow different paths for the same destination in different VRFs.

1. MPLS VPN for different path on Cisco Routers Base MPLS vpn architecture Solution for different path from each VRF. Contact adchen@+886-920-891-782

2. PHY link R1 R2 R4 R3 R5 9.9.23.0/24 .3 .3 .2 .2 .4 .4 .4 .5 .2 .1 9.9.12.0/24 9.9.34.0/24 9.9.24.0/24 9.9.45.0/24 Loopback R1 9.9.1.1/32 R2 9.9.2.2/32 R3 9.9.3.3/32 R4 9.9.4.4/32 R5 9.9.5.5/32

3. VRF R1 R2 R4 R3 R5 A B A B ! ip vrf A rd 99:1 route-target export 99:1 route-target import 99:1 route-target import 99:3 route-target import 99:5 ! ip vrf B rd 99:11 route-target export 99:11 route-target import 99:11 route-target import 99:4 ! ! ip vrf A rd 99:3 route-target export 99:3 route-target import 99:3 route-target import 99:1 route-target import 99:5 ! ip vrf B rd 99:4 route-target export 99:4 route-target import 99:4 route-target import 99:11 ! ! ! interface Loopback99 ip vrf forwarding A ip address 192.168.11.1 255.255.255.0 ! interface Loopback199 ip vrf forwarding B ip address 192.168.111.1 255.255.255.0 ! ! interface Loopback99 ip vrf forwarding A ip address 192.168.33.33 255.255.255.0 ! interface Loopback199 ip vrf forwarding B ip address 192.168.33.3 255.255.255.0 !

4. BGP ASN R1 R2 R4 R3 R5 ALL router in the same AS

5. OSPF area 0 R1 R2 R4 R3 R5 O 9.9.5.5/32 [110/4] via 9.9.12.2, 16:14:12, FastEthernet0/0.12 O 9.9.4.4/32 [110/3] via 9.9.12.2, 16:14:12, FastEthernet0/0.12 O 9.9.3.3/32 [110/3] via 9.9.12.2, 16:14:12, FastEthernet0/0.12 O 9.9.2.2/32 [110/2] via 9.9.12.2, 16:14:12, FastEthernet0/0.12 C 9.9.1.1/32 is directly connected, Loopback0 C 9.9.12.0/24 is directly connected, FastEthernet0/0.12 O 9.9.23.0/24 [110/2] via 9.9.12.2, 16:14:12, FastEthernet0/0.12 O 9.9.24.0/24 [110/2] via 9.9.12.2, 16:14:12, FastEthernet0/0.12 O 9.9.34.0/24 [110/3] via 9.9.12.2, 16:14:12, FastEthernet0/0.12 O 9.9.45.0/24 [110/3] via 9.9.12.2, 16:14:12, FastEthernet0/0.12 R1(config-router-af)# router ospf 1 log-adjacency-changes network 9.9.0.0 0.0.255.255 area 0 ! R1(config-router-af)#do sh ip os ne Neighbor ID Pri State Dead Time Address Interface 9.9.24.2 1 FULL/DR 00:00:33 9.9.12.2 FastEthernet0/0.12 R1(config-router-af)# OSPF cost 200

6. MPLS LDP enable interfaces R1 R2 R4 R3 R5 R2 (config-subif)#do sh mpls ld nei Peer LDP Ident: 9.9.1.1:0; Local LDP Ident 9.9.2.2:0 TCP connection: 9.9.1.1.646 - 9.9.2.2.21205 State: Oper; Msgs sent/rcvd: 1142/1143; Downstream Up time: 16:30:20 LDP discovery sources: FastEthernet0/0.12, Src IP addr: 9.9.12.1 Addresses bound to peer LDP Ident: 9.9.12.1 9.9.1.1 Peer LDP Ident: 9.9.3.3:0; Local LDP Ident 9.9.2.2:0 TCP connection: 9.9.3.3.61681 - 9.9.2.2.646 State: Oper; Msgs sent/rcvd: 1140/1143; Downstream Up time: 16:29:19 LDP discovery sources: FastEthernet0/0.23, Src IP addr: 9.9.23.3 Addresses bound to peer LDP Ident: 9.9.23.3 9.9.34.3 9.9.3.3 Peer LDP Ident: 9.9.4.4:0; Local LDP Ident 9.9.2.2:0 TCP connection: 9.9.4.4.61384 - 9.9.2.2.646 State: Oper; Msgs sent/rcvd: 1149/1142; Downstream Up time: 16:29:12 LDP discovery sources: FastEthernet0/0.24, Src IP addr: 9.9.24.4 Addresses bound to peer LDP Ident: 9.9.24.4 9.9.45.4 9.9.4.4 9.9.34.4 R2(config-subif)# R2 (config-subif)#do sh mpls for Local Outgoing Prefix Bytes tag Outgoing Next Hop tag tag or VC or Tunnel Id switched interface 16 Pop tag 9.9.34.0/24 0 Fa0/0.23 9.9.23.3 17 Pop tag 9.9.4.4/32 125421 Fa0/0.24 9.9.24.4 18 Pop tag 9.9.45.0/24 0 Fa0/0.24 9.9.24.4 19 Pop tag 9.9.1.1/32 374038 Fa0/0.12 9.9.12.1 20 20 9.9.5.5/32 143242 Fa0/0.24 9.9.24.4 21 Pop tag 9.9.3.3/32 280354 Fa0/0.23 9.9.23.3 R2(config-subif)#

7. MP-iBGP peer R1 R2 R4 R3 R5 RR R1 router bgp 9 no synchronization no bgp default route-target filter bgp log-neighbor-changes neighbor 9.9.0.5 remote-as 9 neighbor 9.9.3.3 remote-as 9 neighbor 9.9.3.3 update-source Loopback0 neighbor 9.9.5.5 remote-as 9 neighbor 9.9.5.5 update-source Loopback0 no auto-summary ! address-family vpnv4 neighbor 9.9.3.3 activate neighbor 9.9.3.3 send-community extended neighbor 9.9.3.3 route-reflector-client neighbor 9.9.5.5 activate neighbor 9.9.5.5 send-community extended neighbor 9.9.5.5 route-reflector-client exit-address-family ! Show ip bgp vp all summary Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 9.9.3.3 4 9 1069 1110 13 0 0 14:43:11 2 9.9.5.5 4 9 1050 1095 13 0 0 14:43:10 1 R1(config-router-af)# ASN is 9

8. VRF traffic flow R1 R2 R4 R3 R5 A B A B R1(config-router-af)#do sh ip ro vrf A C 192.168.11.0/24 is directly connected, Loopback99 B 192.168.55.0/24 [200/0] via 9.9.5.5, 14:46:30 B 192.168.33.0/24 [200/0] via 9.9.3.3 , 14:46:30 R1(config-router-af)#do sh ip ro vrf B C 192.168.111.0/24 is directly connected, Loopback199 B 192.168.33.0/24 [20/0] via 9.9.3.3, 01:23:12 R1(config-router-af)# sh ip cef vrf A de 192.168.33.0/24, version 13, epoch 0, cached adjacency 9.9.12.2 0 packets, 0 bytes tag information set local tag: VPN-route-head fast tag rewrite with Fa0/0.12, 9.9.12.2, tags imposed: {21 23} via 9.9.3.3, 0 dependencies, recursive next hop 9.9.12.2, FastEthernet0/0.12 via 9.9.3.3/32 valid cached adjacency tag rewrite with Fa0/0.12, 9.9.12.2, tags imposed: {21 23} R1(config-router-af)#do sh mpls for Local Outgoing Prefix Bytes tag Outgoing Next Hop tag tag or VC or Tunnel Id switched interface 16 Pop tag 9.9.24.0/24 0 Fa0/0.12 9.9.12.2 17 Pop tag 9.9.23.0/24 0 Fa0/0.12 9.9.12.2 18 Pop tag 9.9.2.2/32 0 Fa0/0.12 9.9.12.2 19 17 9.9.4.4/32 0 Fa0/0.12 9.9.12.2 20 16 9.9.34.0/24 0 Fa0/0.12 9.9.12.2 21 18 9.9.45.0/24 0 Fa0/0.12 9.9.12.2 22 20 9.9.5.5/32 0 Fa0/0.12 9.9.12.2 23 21 9.9.3.3/32 0 Fa0/0.12 9.9.12.2 R2(config-subif)# 21 Pop tag 9.9.3.3/32 287059 Fa0/0.23 9.9.23.3 R2(config-subif)#

9. We want different path for vrf R1 R2 R4 R3 R5 A B A B Cisco TE is base on LDP, it’s IGP For the same destination only one path. But How ??

10. The MP-EBGP peer from R4 R1 R2 R4 R3 R5 RR R1 router bgp 9 no synchronization no bgp default route-target filter bgp log-neighbor-changes neighbor 9.9.0.5 remote-as 9 neighbor 9.9.3.3 remote-as 9 neighbor 9.9.3.3 update-source Loopback0 neighbor 9.9.4.4 remote-as 65001 neighbor 9.9.4.4 ebgp-multihop 255 neighbor 9.9.4.4 update-source Loopback0 neighbor 9.9.5.5 remote-as 9 neighbor 9.9.5.5 update-source Loopback0 no auto-summary ! address-family vpnv4 neighbor 9.9.3.3 activate neighbor 9.9.3.3 send-community extended neighbor 9.9.3.3 route-reflector-client neighbor 9.9.4.4 activate neighbor 9.9.4.4 send-community extended neighbor 9.9.4.4 weight 300 neighbor 9.9.4.4 allowas-in neighbor 9.9.5.5 activate neighbor 9.9.5.5 send-community extended neighbor 9.9.5.5 route-reflector-client exit-address-family ! Show ip bgp vp all summary Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 9.9.3.3 4 9 1134 1175 13 0 0 15:48:40 2 9.9.4.4 4 65001 1096 1129 13 0 0 15:48:40 1 9.9.5.5 4 9 1115 1160 13 0 0 15:48:39 1 R1(config-router-af)# AS65001 MP-EBGP MP-iBGP

11. Show result for VRF A on R1 Route Distinguisher: 99:11 (default for vrf B) *> 192.168.33.0 9.9.4.4 300 65001 9 ? *> 192.168.111.0 0.0.0.0 0 32768 ? R1(config-router-af)# R2#sh mpls for | i 205 205 Pop tag 9.9.4.4/32 3732947 Fa0/0.24 9.9.24.4 R2# R1#sh ip cef vrf A 192.168.33.0 de 192.168.33.0/24, version 10, epoch 0, cached adjacency 9.9.12.2 0 packets, 0 bytes tag information set local tag: VPN-route-head fast tag rewrite with Fa0/0.12, 9.9.12.2, tags imposed: {205 409} via 9.9.4.4, 0 dependencies, recursive next hop 9.9.12.2, FastEthernet0/0.12 via 9.9.4.4/32 valid cached adjacency tag rewrite with Fa0/0.12, 9.9.12.2, tags imposed : {205 409} R1# R1 R2 R4 R3 R5 A B A B R1#sh mpls for | i 205 105 205 9.9.4.4/32 0 Fa0/0.12 9.9.12.2 R1# R4(config-router-af)#do sh ip bgp vp all la Network Next Hop In label/Out label Route Distinguisher: 99:3 192.168.33.0 9.9.34.3 409/309 R3#sh mpls for | i 309 309 Aggregate 192.168.33.0/24[V] \ R3#

12. R1#sh ip bgp vp vrf B Network Next Hop Metric LocPrf Weight Path Route Distinguisher: 99:11 (default for vrf B) *> 192.168.111.0 0.0.0.0 0 32768 ? *>i192.168.133.0 9.9.3.3 0 100 0 ? *>i192.168.155.0 9.9.5.5 0 100 0 ? R1# R3#sh mpls for | i 310 310 Aggregate 192.168.133.0/24[V] \ R3#sh ip bgp vp vrf B 192.168.133.0 BGP routing table entry for 99:33:192.168.133.0/24, version 5 Paths: (1 available, best #1, table B) Advertised to update-groups: 2 Local 0.0.0.0 from 0.0.0.0 (9.9.3.3) Origin incomplete, metric 0, localpref 100, weight 32768, valid, sourced, best Extended Community: RT:99:33 mpls labels in/out 310/aggregate(B) R3# R1#sh ip cef vrf B 192.168.133.0 de 192.168.133.0/24, version 17, epoch 0, cached adjacency 9.9.12.2 0 packets, 0 bytes tag information set local tag: VPN-route-head fast tag rewrite with Fa0/0.12, 9.9.12.2, tags imposed: {203 310} via 9.9.3.3, 0 dependencies, recursive next hop 9.9.12.2, FastEthernet0/0.12 via 9.9.3.3/32 valid cached adjacency tag rewrite with Fa0/0.12, 9.9.12.2, tags imposed: {203 310} R1# R1 R2 R4 R3 R5 A B A B R2#sh mpls for | i 203 203 Pop tag 9.9.3.3/32 3728767 Fa0/0.23 9.9.23.3 R2# Show result for VRF B on R1

13. Debug mpls packet R1 to R3 (Path R1---R2-----R4-----R3) R2(config-subif)# *Oct 4 05:45:26.482: MPLS: Fa0/0.12: recvd: CoS=0, TTL=255, Label(s)=17/30 *Oct 4 05:45:26.482: MPLS: Fa0/0.24: xmit: CoS=0, TTL=254, Label(s)=30 R2(config-subif)# R4(config-router)#do deb mpls pa MPLS packet debugging is on R4(config-router)# *Oct 4 05:42:30.686: MPLS: Fa0/0.24: recvd: CoS=0, TTL=254, Label(s)=30 *Oct 4 05:42:30.686: MPLS: Fa0/0.34: xmit: CoS=0, TTL=253, Label(s)=24 R1 R2 R4 R3 R5 A B A B R3 to R1 (Path R3---R4----R2----R1) R2(config-subif)# *Oct 4 05:45:26.486: MPLS: Fa0/0.23: recvd: CoS=0, TTL=255, Label(s)=19/28 *Oct 4 05:45:26.486: MPLS: Fa0/0.12: xmit: CoS=0, TTL=254, Label(s)=28 R2(config-subif)#

14. It’s perfect the each VRF R1 R2 R4 R3 R5 B A A B

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