[c-nsp] IOS XR on ASR9001: Some LDP on Interfaces stuck in xmit

[Dimitris Befas]

Richard, the UDP protocol is being used for LDP hellos exchange. The initial LDP session should be established first via TCP.
It is a good thing you get a connection refused on tcp 646, this means you get an answer from the remote router. Indeed you won't see an "open" message through this telnet, but the aim of this telnet is to see an answer from tcp, even if this answer is "connection refused". If you had a timeout, then it should be a problem.

Do you use the same router IDs for LDP as for your successfully established OSPF neighbors ?

Regards,
Dimitris

-----Original Message-----
From: Richard Hartmann [mailto:richih.mailinglist at gmail.com] 
Sent: Wednesday, March 26, 2014 3:58 PM
To: Dimitris Befas
Cc: Vitkovský Adam; cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] IOS XR on ASR9001: Some LDP on Interfaces stuck in xmit

On Wed, Mar 26, 2014 at 2:49 PM, Dimitris Befas <dimitris.befas at gmail.com> wrote:
> Do you have ip/tcp connectivity between the IP/tcp endpoints of your LDP sessions ?

I do, fwiw, they speak OSPF just fine.


> You may give it a try telneting between your LDP session IPs and towards tcp 646.

That is not a bad idea. I can not connect:

#telnet <peer interface> 646
Trying <peer interface>...
telnet: Unable to connect to remote host: Connection refused

This does not work for loopback IP, either.

I can connect to another ASR running 4.3.0 from the one running 4.3.0 just fine, though.

I am not 100% sure if I should be able to connect while the connection is still not established, though. LDP sessions are established via UDP, after all.


Before you ask, I did try running without an ACL, yes.


Thanks a lot!
Richard