Routing between same VRF instance on different PE routers

[Martorossi]

Consider this topology

R4(g0/1)----------(g0/0)R1(g0/1)----------(g0/2)R2(g0/3)----------(g0/1)R3(g0/0)----------(g0/1)R5

                                                                Provider Network

R1(g0/0)-belongs to Vrf 101:ACME(ip vrf forwarding 101:ACME)-172.16.101.1

R3(g0/0)-belongs to Vrf 101:ACME(ip vrf forwarding 101:ACME)-192.168.202.1

R1-Provider Edge 1 R2-Provider R3-Provider Edge 2 R4-Customer Edge 1 R5-Customer Edge 2

IP Addresses

All interfaces use a subnet mask of 255.255.255.0(/24)

R4 (g0/1)-172.16.101.2 R1 (g0/0)-172.16.101.1 R1 (g0/1)-10.23.0.1 R2 (g0/2)-10.23.0.2

R2 (g0/3)-10.34.0.2 R3(g0/1)-10.34.0.3 R3(g0/0)-192.168.202.1 R5(g0/1)-192.168.202.2

Configuration

R1

Ip vrf 101:ACME

rd 1.1.1.1:1

address-family ipv4

route-target export 1.1.1.1:101

route-target import 3.3.3.3:101

R3

Ip vrf 101:ACME

rd 3.3.3.3:1

address-family ipv4

route-target export 3.3.3.3:101

route-target import 1.1.1.1:101

Ospf process id 1 is configured for interfaces on R1(g0/1),R2(g0/2),R2(g0/3), R3(g0/1) hence R1 can ping R3(g0/1)-10.34.0.3

R1#ping vrf 101:ACME 172.16.101.1 successful

R1#ping vrf 101:ACME 192.168.202.1 (not successful)

What can be done about the configuration to enable R1 ping R3(g0/0)-192.168.202.1 successfully

[Nagendra Kumar Nainar]

You have to enable MP-BGP with VPNv4 address family enabled on R1 and R3 and redisribute the vrf prefix into BGP.

Below link will be helpful:

http://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching-mpls/mpls/13733-mpls-vpn-basic.html

[Martorossi]

I am still having problem with the ping

R1#ping vrf 101:ACME 192.168.202.1

What I did

I created Loopback 0 of 1.1.1.1 on R1,3.3.3.3 on R3 and advertised it under router ospf 1

Router 1

Router ospf 101 vrf 101:ACME

network 172.16.101.0 0.0.0.255 area 0

redistribute bgp 64512 subnets

Router bgp 64512

neighbor 3.3.3.3 remote as 64512

neighbor 3.3.3.3 update-source Loopback 0

address-family vpnv4

neighbor 3.3.3.3 activate

neighbour 3.3.3.3 send-community extended

address-family ipv4 vrf 101:ACME

redistribute ospf 101 vrf 101:ACME

Router 3

Router ospf 101 vrf 101:ACME

Network 192.168.202.0 0.0.0.255 area 0

Redistribute 64512 subnets

Router bgp 64512

neighbor 1.1.1.1 remote as 64512

neighbor 1.1.1.1 update-source Loopback 0

address-family vpnv4

neighbor 1.1.1.1 activate

neighbour 1.1.1.1 send-community extended

address-family ipv4 vrf 101:ACME

redistribute ospf 101 vrf 101:ACME

The Bgp neighborship between R1(1.1.1.1) and R3(3.3.3.3) is up and ok.

[Nagendra Kumar Nainar]

Hi,

Do you see those prefixes advertised by BGP to neighbor?. Do you see if it is installed in vrf routing table?.

Can you check "show ip bgp vpnv4 all" on both the PE devices and "show ip route vrf <vrf-name>" and see if it is populated?.

[Nagendra Kumar Nainar]

Just to add, I hope you have MPLS enabled on all core facing interfaces on PE and P routers.

[Martorossi]

This is the output

R1#show ip route vrf 101:ACME

      172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks

C        172.16.101.0/24 is directly connected, FastEthernet1/0

L        172.16.101.1/32 is directly connected, FastEthernet1/0

B     192.168.202.0/24 [200/0] via 3.3.3.3, 01:45:09

R1#                

R3#show ip route vrf 101:ACME

      172.16.0.0/24 is subnetted, 1 subnets

B        172.16.101.0 [200/0] via 1.1.1.1, 01:47:08

      192.168.202.0/24 is variably subnetted, 2 subnets, 2 masks

C        192.168.202.0/24 is directly connected, FastEthernet1/1

L        192.168.202.1/32 is directly connected, FastEthernet1/1

R3#                  

R1#show ip bgp vpnv4 all

   Network          Next Hop            Metric LocPrf Weight Path

Route Distinguisher: 1.1.1.1:1 (default for vrf 101:ACME)

*> 172.16.101.0/24  0.0.0.0                  0         32768 ?

*>i192.168.202.0    3.3.3.3                  0    100      0 ?

Route Distinguisher: 3.3.3.3:1

*>i192.168.202.0    3.3.3.3                  0    100      0 ?

R1#

R3#show ip bgp vpnv4 all

 Network          Next Hop            Metric LocPrf Weight Path

Route Distinguisher: 1.1.1.1:1

*>i172.16.101.0/24  1.1.1.1                  0    100      0 ?

Route Distinguisher: 3.3.3.3:1 (default for vrf 101:ACME)

*>i172.16.101.0/24  1.1.1.1                  0    100      0 ?

*> 192.168.202.0    0.0.0.0                  0         32768 ?

R3#

Mpls is enabled on R1,R2 and R3 specifically R1(g0/1),R2(g0/2),R2(g0/3) and R3(g0/1), as for my output interfaces they are different from the gigabitethernet interfaces because I used fastethernet interfaces on GNS3. I enabled Mpls globally on R1,R2 and R3 with Mpls ip command.

R1-MPLS label range 100 199,R1(g0/1)-Mpls ip

R2-MPLS label range 200 299,R2(g0/2),R2(g0/3)-Mpls ip

R3-MPLS label range 300 399, R3(g0/1)-Mpls ip

Did not resolve the ping issue of

R1#ping vrf 101:ACME 192.168.202.1

[Nagendra Kumar Nainar]

Do you have MPLS enabled on the core interfaces?. Can you check "show ip cef vrf <> <prefix>" and see if proper labels are imposed?.

Get "show mpls forwarding" as well

[Martorossi]

R1#show ip cef vrf 101:ACME            

Prefix               Next Hop             Interface

0.0.0.0/0            no route

0.0.0.0/8            drop

0.0.0.0/32          receive             

127.0.0.0/8        drop

172.16.101.0/24      attached             FastEthernet1/0

172.16.101.0/32      receive                FastEthernet1/0

172.16.101.1/32      receive                FastEthernet1/0

172.16.101.2/32      attached              FastEthernet1/0

172.16.101.255/32 receive                 FastEthernet1/0

192.168.202.0/24     10.23.0.2           FastEthernet1/1

224.0.0.0/4          drop

224.0.0.0/24       receive             

240.0.0.0/4          drop

255.255.255.255/32   receive             

R3#show ip cef vrf 101:ACME

Prefix               Next Hop             Interface

0.0.0.0/0            no route

0.0.0.0/8            drop

0.0.0.0/32          receive             

127.0.0.0/8        drop

172.16.101.0/24      10.34.0.2            FastEthernet1/0

192.168.202.0/24     attached            FastEthernet1/1

192.168.202.0/32     receive               FastEthernet1/1

192.168.202.1/32     receive               FastEthernet1/1

192.168.202.2/32     attached             FastEthernet1/1

192.168.202.255/32 receive               FastEthernet1/1

224.0.0.0/4          drop

224.0.0.0/24       receive             

240.0.0.0/4          drop

255.255.255.255/32   receive             

R1#show mpls forwarding-table

Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop   

Label      Label      or Tunnel Id     Switched      interface             

16         No Label   172.16.101.0/24[V]   \

                                       0             aggregate/101:ACME

100        No Label      2.2.2.2/32        0           Fa1/1      10.23.0.2  

101        201               3.3.3.3/32       0           Fa1/1      10.23.0.2  

102        Pop Label    10.34.0.0/24   0            Fa1/1      10.23.0.2  

R3#show mpls forwarding-table

Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop   

Label      Label      or Tunnel Id     Switched      interface             

16         No Label   192.168.202.0/24[V]   \

                                       0             aggregate/101:ACME

300        200             1.1.1.1/32         0            Fa1/0      10.34.0.2  

301        No Label     2.2.2.2/32         0            Fa1/0      10.34.0.2  

302        Pop Label  10.23.0.0/24    0             Fa1/0      10.34.0.2    

[Nagendra Kumar Nainar]

Hi,

It seems the labels are assigned and exchanged. Can you check the below:

1. On R1, check "show ip cef vrf 101:ACME 192.168.202.0 255.255.255.0" and see if it pushes labels {16, 201}

2. On R3, check "show ip cef vrf 101:ACME 172.16.101.0 255.255.255.0" and see if pushes labels {16, 200}.

Also try "ping mpls ipv4 1.1.1.1 255.255.255.255" from R3 and "ping mpls ipv4 3.3.3.3 255.255.255.255" from R1.

-Nagendra

[Martorossi]

I have concluded on the issue, It should be an IOS problem because the route of 192.168.202.0/24 is in the vrf routing table 101:ACME(show ip route vrf 101:ACME) as a bgp learned route in R1.