[c-nsp] auto-backup tunnels

[Koltsov, Aleksey (NSN - DE/Dusseldorf)]

Hi Oliver,

I have exactly this topology:

PE     P      P     PE
 
R1----R2-----R3-----R4
|     |       |      |
|     |       |      |
|     |       |      |
R5----R6-----R7-----R8

And if I crash all links of R3 and R2, and then restore them, I can see
that following backup tunnels appeared (I replaced IPs with hostnames):

R1#sh mpls traffic-eng tunnels backup
R1_t8000
  LSP Head, Tunnel8000, Admin: up, Oper: up
  Src R1, Dest R2, Instance 7
  Fast Reroute Backup Provided:
    Protected i/fs: PO4/0/3
    Protected lsps: 0 Active lsps: 0
    Backup BW: any pool unlimited; inuse: 0 kbps
R1_t8001
  LSP Head, Tunnel8001, Admin: up, Oper: up
  Src R1, Dest R3, Instance 12
  Fast Reroute Backup Provided:
    Protected i/fs: PO4/0/3
    Protected lsps: 0 Active lsps: 0
    Backup BW: any pool unlimited; inuse: 0 kbps
R1_t8002
  LSP Head, Tunnel8002, Admin: up, Oper: up
  Src R1, Dest R6, Instance 1
  Fast Reroute Backup Provided:
    Protected i/fs: PO4/0/3
    Protected lsps: 2 Active lsps: 0
    Backup BW: any pool unlimited; inuse: 2000 kbps
R1_t8003
  LSP Head, Tunnel8003, Admin: up, Oper: up
  Src R1, Dest R7, Instance 1
  Fast Reroute Backup Provided:
    Protected i/fs: PO4/0/3
    Protected lsps: 0 Active lsps: 0
    Backup BW: any pool unlimited; inuse: 0 kbps
R1_t8004
  LSP Head, Tunnel8004, Admin: up, Oper: up
  Src R1, Dest R4, Instance 1
  Fast Reroute Backup Provided:
    Protected i/fs: PO4/0/3
    Protected lsps: 0 Active lsps: 0
    Backup BW: any pool unlimited; inuse: 0 kbps

All of them seems to be correct except Tunnel8003 and 8004 which point
to NNNHOP instead NHOP and NNHOP.

The routers have IOS 12.2(33)SRD3.


-----Original Message-----
From: ext Oliver Boehmer (oboehmer) [mailto:oboehmer at cisco.com] 
Sent: Tuesday, September 28, 2010 2:01 PM
To: Koltsov, Aleksey (NSN - DE/Dusseldorf); cisco-nsp at puck.nether.net
Subject: RE: [c-nsp] auto-backup tunnels

Aleksey,

> So, as it could be seen from the config above, both NHOP and NNHOP
> backup tunnels are setup. But when I crash the network like to
shutdown
> R2 and R3 I can see that, for example, R1 builds a backup tunnel from
R1
> to R4 which is neither NHOP nor NNHOP tunnel. So here is my question
why
> it happens? Is it expected behaviour or not?

It is not expected, the PLR should only build NHOP and NNHOP.. If there
is indeed a tunnel from R1 to R4 in your topology, something went wrong,
or your topology is indeed different.
Can you check if this tunnel protects any LSP?

	oli