MPLS Routing Issues Between CE and Shared Services VPN - Routes are present etc..

[finlaysoni]

**** DIAGRAM AND CONFIGS/OUTPUT ATTACHED ****

Hi all,

I have been working on a GNS3 MPLS Lab. It consists of 12 Routers as follows:

4 x PE Routers
1 x P Router
2 Customers with 3 x CE Routers Each (HQ, 1 and 2)
An Internet Router (To provide Inet Routes)
A Shared Services Router (Loopback 100 on PE1)

Just until today this was all working fine. I pushed on with my configs to add Internet Services etc, Then I noticed the Shared Services stopped working. I undid the Internet Configs and shut down extra interfaces that I added in today, still to no avail...

See Diagrams and Configs...

My CE Router (AHQ) can see the Shared Services Route in its RIB which

is 192.168.100.0 / 24. 

AHQ is attached to PE2 on vrf CUST-A.

On PE2 vrf CUST-A Routing Table has both the routes for the Shared Services Network and the AHQ Loopbacks.

PE2 connects to PE1, and PE1 also has these routes in vrf CUST-A.

My CUST-A vrf uses an export map to tag an additive RT onto its prefixes that are being advertised out. It also imports the RT of the Shared Services VRF.

The SHARED vrf imports these routes as they are tagged from the PEs etc.

This all works fine as I can see all the relevant routes in the correct places and VRFs etc...

I've checked the VRF forwarding tables, CEF tables, VRFs etc, and all looks good. However I just can't ping from AHQ to Shared Services Server or vice versa...

If I traceroute from the CE AHQ It goes as far as PE2 and then **** out....
If I traceroute to another site like CE A1, it traces fully and I can see the MPLS labels in the trace etc...

I am a bit at a loss here and would appreciate any help with this matter...
This is my first time posting, so I am going to try and attach the relevant outputs and diagrams as files etc...

Thank you...

Ian.

The Affected Path on the Diagram is AHQ -> PE2 -> PE1 or vice versa....

[bhnegi · Accepted solution]

Can you check if you have ldp adjacency up between PE1 and PE2?

PE2#sh mpls forwarding-table
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop    
tag    tag or VC   or Tunnel Id      switched   interface              
16     Untagged    1.1.1.1/32        0          Fa0/0      192.168.1.1  >>>>>>>>>>>>> should be pop

PE1#sh mpls forwarding-table
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop    
tag    tag or VC   or Tunnel Id      switched   interface              
16     Untagged    20.20.20.20/32    0          Fa0/0      192.168.1.2  
17     Untagged    2.2.2.2/32        0          Fa0/0      192.168.1.2  >>>>>>>>>>>>should be pop

Best Regards,

Bheem

[finlaysoni]

Thank you sir, you are spot on..

Can't believe I missed that :o

I had made some extra loopbacks at the start of the MPLS Lab just to practise redistributing at the PE level into the local BGP config. When I started with the Internet setup I just wanted to clean up some routes and not have extra routes in the main BGP table that I didn't need. 

PE 1 had loopback 1 set to 1.1.1.1 and loopback 10 set to 10.10.10.10 along with others. I didn't want the 10.10.10.10 any more and of course that's what MPLS was using as it's RID.

Learned 2 valuable lessons here lol - 

1) Always Hard Code the MPLS LDP RIDs

2) Never just assume that the LDP Neigborship is fine because it was ok earlier in the day :)

Thanks a lot for your help. I've fixed it all now and it's working exactly as it should be again....

Cheers,

Ian.

[bhnegi]

Hi Ian

Glad to hear everything is working fine!

Best Regards,

Bheem