l2vpn neighbor all ldp flap command usage

[Rojer-bkk]

Hi Expert,

In l2vpn targeted LDP sessions/pseudowires between Cisco and 3rd party vendors, could someone explain me how the command work and help to solve inter-operability issue? Thanks in advance.

[Vinit Jain]

Hi,
Could you please help me understand your problem. Is your targeted LDP session getting established? Is the l2vpn peering up?
Could you please capture the below output:
- show mpls ldp nei <remote-PE-IP>
- show xconnect all
- show mpls l2 vc <vcid> det
If your t-ldp session is not getting established, could you please try configuring "mpls ldp discovery targeted-hello accept".
Thanks
--VJ

[ms.borikarn.th]

Hi VJ,

Thanks for reply.
Connectivity is l2vpn xconnect stitching (Cisco 9K(A)----- Cisco9K(B) ----- 3rd party)
Cisco9K(B) is stitching node. The problem is when i removed 3rd party peer IP address on Cisco9K(B), i got the step as below
- Cisco9K(B) sent 'LDP withdrawal msg' to 3rd party
- 3rd party response by sent 'LDP release msg' to Cisco9K(B)
- 3rd party also sent 'LDP withdrawl msg' to Cisco9K(B)
- No any response from Cisco9K(B). 3rd party stuck in 'wait release' and still keep label
- Put the 3rd party neighbor peer back, Cisco9K(B) sent 'LDP label req' to 3rd party.
- No any response for label mapping from 3rd party device.

With steps above, on Cisco9K(B), the remote label in segment 2 (3rd party) is unknown and then cause Cisco9K(B) unable to assign local label to segment 1 (Cisco9K(A)) as output in attached. T-LDP still be established.

I'd like to understand the l2vpn command 'neighbor all ldp flap' works. In lab testing, it's working to solve interop issue.
I think the command will take effect to T-LDP (reset/flap) only particular PW, but not for other T-LDP sessions on other PWs. Please correct me if i'm wrong. Thanks in advance.