Monday, November 28, 2011

Cisco Inter-AS Mpls VPN with multihop VPNv4 route exchange

In this blog we will do Inter-AS Mpls VPN with multihop VPNv4 route exchange configuration at AS edge PE routers.Here is the topology for this blog:


We will run Eigrp 100 as vrf routing protocol between CE-1 and AS1234-PE1 routers.
We will run rip as vrf routing protocol between CE-2 and AS5678-PE1 routers.
We will eBGP vpnv4 between PE-2 routers.
We will run  OSPF as IGP and MP-BGP between AS1234 PE1-PE2 and P routers.P router will be route-reflector.
We will run OSPF as IGP and MP-BGP between AS5678 PE1-PE2 and P routers.P router will be route-reflector.
All routers in this example are Cisco Systems 3725 router.Any other Cisco router that support Mpls VPN could be used for this example.Cisco IOS version should be checked  on routers before configuring Inter-AS Mpls VPN with multihop VPNv4 route exchange
Here is the configurations:

Configuration of CE-1

interface Loopback0
 ip address 1.1.1.1 255.255.255.255
interface Loopback11
 ip address 11.11.11.11 255.255.255.255
interface FastEthernet0/0
 ip address 12.12.12.1 255.255.255.0
router eigrp 100
 redistribute connected
 network 1.0.0.0
 network 12.12.12.1 0.0.0.0
 no auto-summary

Configuration of AS1234-PE1
ip vrf a
 rd 1234:1
 route-target export 1234:1
 route-target import 1234:1
 route-target import 5678:1
!
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
  ip ospf 1 area 0
!
interface FastEthernet0/0
 ip address 192.168.23.2 255.255.255.0
ip ospf network point-to-point
mpls ip
!
interface FastEthernet0/1
 ip vrf forwarding a
 ip address 12.12.12.2 255.255.255.0

router eigrp 1
 no auto-summary
 !
 address-family ipv4 vrf a
  redistribute bgp 1234
  network 12.12.12.2 0.0.0.0
  default-metric 1000 100 255 1 1500
  no auto-summary
  autonomous-system 100
 exit-address-family
!
router ospf 1
 log-adjacency-changes
 network 192.168.0.0 0.0.255.255 area 0
!
router bgp 1234
 no synchronization
 bgp log-neighbor-changes
 neighbor 3.3.3.3 remote-as 1234
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 7.7.7.7 remote-as 5678
 neighbor 7.7.7.7 ebgp-multihop 255
 neighbor 7.7.7.7 update-source Loopback0
 no auto-summary
 !
 address-family vpnv4
  neighbor 3.3.3.3 activate
  neighbor 3.3.3.3 send-community extended
  neighbor 7.7.7.7 activate
  neighbor 7.7.7.7 send-community extended
 exit-address-family
 !
 address-family ipv4 vrf a
  redistribute connected
  redistribute static
  redistribute eigrp 100
  no synchronization
 exit-address-family
Configuration of AS1234-P

interface Loopback0
 ip address 3.3.3.3 255.255.255.255
 ip ospf 1 area 0
!
interface FastEthernet0/0
 ip address 192.168.23.3 255.255.255.0
ip ospf network point-to-point
mpls ip
!        
interface FastEthernet0/1
 ip address 192.168.34.3 255.255.255.0
mpls ip
!
router ospf 1
 log-adjacency-changes
 network 192.168.0.0 0.0.255.255 area 0
!
router bgp 1234
 no synchronization
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 1234
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 4.4.4.4 remote-as 1234
 neighbor 4.4.4.4 update-source Loopback0
 no auto-summary
 !
 address-family vpnv4
  neighbor 2.2.2.2 activate
  neighbor 2.2.2.2 send-community extended
  neighbor 2.2.2.2 route-reflector-client
  neighbor 4.4.4.4 activate
  neighbor 4.4.4.4 send-community extended
  neighbor 4.4.4.4 route-reflector-client
 exit-address-family

Configuration of AS1234-PE2:

interface Loopback0
 ip address 4.4.4.4 255.255.255.255
ip ospf 1 area 0
!
interface FastEthernet0/0
 ip address 192.168.34.4 255.255.255.0
mpls ip
!
interface FastEthernet0/1.10
 encapsulation dot1Q 10
 ip address 192.168.45.4 255.255.255.0
!
router ospf 1
 log-adjacency-changes
 redistribute bgp 1234 subnets
 passive-interface FastEthernet0/1.10
 network 192.168.0.0 0.0.255.255 area 0
!
router bgp 1234
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor 3.3.3.3 remote-as 1234
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 192.168.45.5 remote-as 5678
 !
 address-family ipv4
  neighbor 3.3.3.3 activate
  neighbor 192.168.45.5 activate
  neighbor 192.168.45.5 route-map as5678-out out
  neighbor 192.168.45.5 send-label
  no auto-summary
  no synchronization
  network 2.2.2.2 mask 255.255.255.255
 exit-address-family
 !
 address-family vpnv4
  neighbor 3.3.3.3 activate
  neighbor 3.3.3.3 send-community extended
  neighbor 3.3.3.3 next-hop-self
 exit-address-family

ip prefix-list PE seq 5 permit 2.2.2.2/32
!
route-map as5678-out permit 10
 match ip address prefix-list PE
 set mpls-label

Configuration AS5678-PE2

interface Loopback0
 ip address 5.5.5.5 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.56.5 255.255.255.0
mpls ip
!
interface FastEthernet0/1.10
 encapsulation dot1Q 10
 ip address 192.168.45.5 255.255.255.0
!
router ospf 1
 router-id 5.5.5.5
 log-adjacency-changes
 redistribute bgp 5678 subnets
 passive-interface FastEthernet0/1.10
 network 5.5.5.5 0.0.0.0 area 0
 network 192.168.0.0 0.0.255.255 area 0
!
router bgp 5678
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor 6.6.6.6 remote-as 5678
 neighbor 6.6.6.6 update-source Loopback0
 neighbor 192.168.45.4 remote-as 1234
 !
 address-family ipv4
  neighbor 6.6.6.6 activate
  neighbor 192.168.45.4 activate
  neighbor 192.168.45.4 route-map as1234-out out
  neighbor 192.168.45.4 send-label
  no auto-summary
  no synchronization
  network 7.7.7.7 mask 255.255.255.255
 exit-address-family
 !
 address-family vpnv4
  neighbor 6.6.6.6 activate
  neighbor 6.6.6.6 send-community extended
  neighbor 6.6.6.6 next-hop-self
 exit-address-family
!
ip prefix-list PE seq 5 permit 7.7.7.7/32
!
route-map as1234-out permit 10
 match ip address prefix-list PE
 set mpls-label

Configuration of AS5678-P:

interface Loopback0
 ip address 6.6.6.6 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.56.6 255.255.255.0
mpls ip
!
interface FastEthernet0/1
 ip address 192.168.67.6 255.255.255.0
mpls ip
!
router ospf 1
 router-id 6.6.6.6
 log-adjacency-changes
 network 6.6.6.6 0.0.0.0 area 0
 network 192.168.0.0 0.0.255.255 area 0
!
router bgp 5678
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 neighbor 5.5.5.5 remote-as 5678
 neighbor 5.5.5.5 update-source Loopback0
 neighbor 7.7.7.7 remote-as 5678
 neighbor 7.7.7.7 update-source Loopback0
 !
 address-family ipv4
  neighbor 5.5.5.5 activate
  neighbor 7.7.7.7 activate
  no auto-summary
  no synchronization
 exit-address-family
 !
 address-family vpnv4
  neighbor 5.5.5.5 activate
  neighbor 5.5.5.5 send-community extended
  neighbor 5.5.5.5 route-reflector-client
  neighbor 7.7.7.7 activate
  neighbor 7.7.7.7 send-community extended
  neighbor 7.7.7.7 route-reflector-client
 exit-address-family

Configuration AS5678-PE1:

ip vrf a
 rd 5678:1
 route-target export 5678:1
 route-target import 5678:1
 route-target import 1234:1
!
interface Loopback0
 ip address 7.7.7.7 255.255.255.255
!
interface FastEthernet0/0
 ip address 192.168.67.7 255.255.255.0
mpls ip
!
interface FastEthernet0/1
 ip vrf forwarding a
 ip address 78.78.78.7 255.255.255.0
!
router ospf 1
 router-id 7.7.7.7
 log-adjacency-changes
 network 7.7.7.7 0.0.0.0 area 0
 network 192.168.0.0 0.0.255.255 area 0
!
router rip
 !
 address-family ipv4 vrf a
  redistribute bgp 5678 metric 1
  network 78.0.0.0
  no auto-summary
  version 2
 exit-address-family
!
router bgp 5678
 no synchronization
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 1234
 neighbor 2.2.2.2 ebgp-multihop 255
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 6.6.6.6 remote-as 5678
 neighbor 6.6.6.6 update-source Loopback0
 no auto-summary
 !
 address-family vpnv4
  neighbor 2.2.2.2 activate
  neighbor 2.2.2.2 send-community extended
  neighbor 6.6.6.6 activate
  neighbor 6.6.6.6 send-community extended
 exit-address-family
 !
 address-family ipv4 vrf a
  redistribute rip
  no synchronization
 exit-address-family

Configuration of CE-2

interface Loopback0
 ip address 8.8.8.8 255.255.255.255
!
interface FastEthernet0/0
 ip address 78.78.78.8 255.255.255.0
!
router rip
 version 2
 network 8.0.0.0
 network 78.0.0.0
 no auto-summary

Lets check reachability between  CE routers:
CE1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
     8.0.0.0/32 is subnetted, 1 subnets
D EX    8.8.8.8 [170/2611200] via 12.12.12.2, 00:31:15, FastEthernet0/0
     78.0.0.0/24 is subnetted, 1 subnets
D EX    78.78.78.0 [170/2611200] via 12.12.12.2, 00:31:15, FastEthernet0/0
     11.0.0.0/32 is subnetted, 1 subnets
C       11.11.11.11 is directly connected, Loopback11
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0

R1#ping 8.8.8.8 source 1.1.1.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 8.8.8.8, timeout is 2 seconds:
Packet sent with a source address of 1.1.1.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 632/844/1064 ms
CE1#trace
Protocol [ip]:
Target IP address: 8.8.8.8
Source address: 1.1.1.1
Numeric display [n]: yes
Timeout in seconds [3]:
Probe count [3]:
Minimum Time to Live [1]:
Maximum Time to Live [30]:
Port Number [33434]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Type escape sequence to abort.
Tracing the route to 8.8.8.8

  1 12.12.12.2 244 msec 132 msec 256 msec
  2 192.168.23.3 [MPLS: Labels 20/20 Exp 0] 736 msec 896 msec 1244 msec
  3 192.168.34.4 [MPLS: Labels 20/20 Exp 0] 1444 msec 784 msec 788 msec
  4 192.168.45.5 [MPLS: Labels 16/20 Exp 0] 1008 msec 1404 msec 1304 msec
  5 192.168.56.6 [MPLS: Labels 16/20 Exp 0] 2000 msec 1968 msec 1756 msec
  6 78.78.78.7 [MPLS: Label 20 Exp 0] 2272 msec 2388 msec 2812 msec
  7 78.78.78.8 1704 msec 1092 msec 2160 msec

Lets check the vrf a routing tables and LSP:

AS1234-PE#show ip route vrf a

Routing Table: a
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     1.0.0.0/32 is subnetted, 1 subnets
D       1.1.1.1 [90/409600] via 12.12.12.1, 00:09:53, FastEthernet0/1
     8.0.0.0/32 is subnetted, 1 subnets
B       8.8.8.8 [20/1] via 7.7.7.7, 00:00:08
     78.0.0.0/24 is subnetted, 1 subnets
B       78.78.78.0 [20/0] via 7.7.7.7, 00:00:09
     11.0.0.0/32 is subnetted, 1 subnets
D EX    11.11.11.11 [170/409600] via 12.12.12.1, 00:09:53, FastEthernet0/1
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/1

AS1234-PE#show ip cef vrf a 8.8.8.8
8.8.8.8/32, version 14, epoch 0, cached adjacency 192.168.23.3
0 packets, 0 bytes
  tag information set
    local tag: VPN-route-head
    fast tag rewrite with Fa0/0, 192.168.23.3, tags imposed: {20 20}
  via 7.7.7.7, 0 dependencies, recursive
    next hop 192.168.23.3, FastEthernet0/0 via 7.7.7.7/32
    valid cached adjacency
    tag rewrite with Fa0/0, 192.168.23.3, tags imposed: {20 20}
We see that VPN label is 20 and transport label is 20 for next-hop 7.7.7.7
Lets check AS1234-P`s LFIB table for transport label 20:

AS1234-P #sh mpls forwarding-table labels 20
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface              
20     20          7.7.7.7/32        1084       Fa0/1      192.168.34.4
Edge router`s LFIB table:
AS1234-Edge#show mpls forwarding-table labels 20
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface              
20     16          7.7.7.7/32        1677       Fa0/1.10   192.168.45.5
This transport label for 7.7.7.7 is 16.This label comes via BGP (we had added send-label for tunnels.See the configurations of edge routers.)
AS1234-Edge #show ip bgp neighbor 192.168.45.5
BGP neighbor is 192.168.45.5,  remote AS 5678, external link
  BGP version 4, remote router ID 5.5.5.5
  BGP state = Established, up for 00:13:37
  Last read 00:00:37, last write 00:00:36, hold time is 180, keepalive interval is 60 seconds
  Neighbor capabilities:
    Route refresh: advertised and received(old & new)
    Address family IPv4 Unicast: advertised and received
    ipv4 MPLS Label capability: advertised and received


AS5678-Edge#show mpls forwarding-table labels 16
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface             
16     16          7.7.7.7/32        2025       Fa0/0      192.168.56.6
AS5678-P#show mpls forwarding-table labels 16
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface             
16     Pop tag     7.7.7.7/32        7779       Fa0/1      192.168.67.7

PHP router removes the outer tag and last PE router has only vpn label:

AS5678-PE#sh mpls forwarding-table labels 20
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface             
20     Untagged    8.8.8.8/32[V]     84         Fa0/1      78.78.78.8

We see that end-to-end LSP is working.
Inter-AS Mpls VPN with multihop VPNv4 route exchange configuration`s key points:
-          Send-label command between Inter-AS routers
-          Redistribution of eBGP into IGP on Inter-AS routers.But be careful, only loopback ip addresses of neighbor AS should be redistributed.
-          When route-map is done between Inter-AS peers, send-label command doesnt work by itself.There should also be set mpls-label command under route-map.

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