[j-nsp] RSVP session tear message

[Khairul Alam]

Hello all,

 

We have been facing some problems regarding RSVP sessions recently. It is
visible that rsvp session has been teared up and restored, but along the
same path and same hop. Extensive review has revealed nothing which would
explain this tear and the 're-routed' path seems to be exactly what it was
before. Before this the LSP had been re-routed on a previous occasion and
RSVP tunnel reconfigured over another part but no reason could be pointed
out regarding that either.

The rsvp session stats and configuration is listed below.

 

khairul at FPSDR07-HO> show configuration protocols mpls


label-switched-path Robi_Pubail-Faridpur {


    to 10.55.100.128;


    no-cspf;


    node-link-protection;


    primary P1-Robi_Pubail-Faridpur;


}


path P1-Robi_Pubail-Faridpur {


    10.85.100.128 loose;


    10.73.0.129 strict;


    10.1.0.130 strict;

 

khairul at FPSDR07-HO> show rsvp session ingress lsp name Robi_Pubail-Faridpur
extensive


Ingress RSVP: 2 sessions


 


10.55.100.128


  From: 10.49.100.128, LSPstate: Up, ActiveRoute: 0


  LSPname: Robi_Pubail-Faridpur, LSPpath: Primary


  LSPtype: Static Configured


  Suggested label received: -, Suggested label sent: -


  Recovery label received: -, Recovery label sent: 785776


  Resv style: 1 SE, Label in: -, Label out: 785776


  Time left:    -, Since: Tue Jan 26 13:41:33 2016


  Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500


  Port number: sender 7 receiver 64750 protocol 0


  Node/Link protection desired


  Type: Node/Link protected LSP, using Bypass->10.49.100.6->10.93.100.9


     1089 Feb 16 11:59:23 Node protection up, using
Bypass->10.49.100.6->10.93.100.9


     1088 Feb 16 11:59:23 Link protection down, LSP rerouted


     1087 Feb 16 11:59:14 Link protection up, using Bypass->10.49.100.6


     1086 Feb 16 11:59:14 Node protection down, RSVP session down


     1085 Feb 16 11:56:00 Node protection up, using
Bypass->10.49.100.6->10.93.100.9


     1084 Feb 16 11:56:00 Link protection down, LSP rerouted


     1083 Feb 16 11:55:54 Link protection up, using Bypass->10.49.100.6


     1082 Feb 16 11:55:52 Bypass in down state, Bypass->10.49.100.6


     1081 Feb 16 11:55:51 New bypass Bypass->10.49.100.6


     1080 Feb 16 11:55:51 Node protection down, RSVP session down


     1079 Feb 16 11:12:33 Node protection up, using
Bypass->10.49.100.6->10.93.100.9


     1078 Feb 16 11:12:31 Bypass in down state, Bypass->10.49.100.6


     1077 Feb 16 11:12:31 New bypass Bypass->10.49.100.6


     1076 Feb 16 11:12:28 New bypass Bypass->10.49.100.6->10.93.100.9


     1075 Feb 16 11:10:17 Link protection down, sending ResvTear on LSP


     1074 Feb 16 11:10:16 Link protection up, using Bypass->10.129.100.2


  PATH rcvfrom: localclient


  Adspec: sent MTU 1500


  Path MTU: received 1500


  PATH sentto: 10.49.100.6 (ge-1/2/9.0) 3682 pkts


  RESV rcvfrom: 10.49.100.6 (ge-1/2/9.0) 889 pkts


  Explct route: 10.49.100.6 10.85.100.128 10.73.0.129 10.1.0.130


  Record route: <self> 10.49.103.130 (node-id) 10.49.100.6 10.93.100.128
(node-id) 10.93.100.9 10.67.100.128 (node-id) 10.67.100.1 10.85.100.129
(node-id)             

  10.85.100.9 10.85.100.128 (node-id) 10.85.100.5 10.73.0.129 (node-id)
10.85.100.14 10.1.0.130 (node-id) 10.73.100.241 10.1.0.131 (node-id)
10.1.0.18                 

  10.55.100.128 (node-id) 10.1.100.78


Total 1 displayed, Up 1, Down 0      

 

The part marked Yellow is the one which shows the ResvTear message and a new
re-routed LSP route at the loose end, but the green marked part shows 'lsp
rerouted' and 'rsvp session down' messages but as you can see it 're-routes'
back to the exact same hop and there is no ResvTear message received. It is
also mentionable that none of the IP were unreachable, none of the
interfaces flapped, no is-is adjacency was down in either of the green or
yellow marked cases which would possibly have caused a re-route of the LSP.

This is a shout-out to the community. Any explanation regarding the issue
would be very helpful to us as our troubleshooting could not point the
reason.

 

Thanks in advance,

Khairul