Re: FRR NHOP tunnel disappear after failure. Im about smashing

What are your path options? Where is the backup tunnel applied? When the primary path goes down you should be able to quickly do a traceroute and see the extra FRR label in the stack.

Also remember that FRR is a temporary bandaid. When the primary path goes down the tunnel is automatically fast rerouted to the backup tunnel. However shortly after that the headend will reoptimize to a new dynamic path, which avoids the backup tunnel and the extra FRR label.

Brian McGahan, CCIE #8593 (R&S/SP/Security)
bmcgahan_at_INE.com

Internetwork Expert, Inc.
http://www.INE.com

On Jul 3, 2012, at 11:01 PM, "jeremy co" <jeremy.cool14_at_gmail.com> wrote:

> Hi,
>
> I faced a very weird issue with NHOP tunnels. Everything looks good until
> next hop fails. I can see are *ready* and after failure back up tunnels
> become *active* and then after couple of seconds I cannot see them in FRR
> database anymore!!!!!!!
>
>
>
> interface Tunnel101
> description Primary tunnel
> ip unnumbered Loopback0
> load-interval 30
> mpls ip
> tunnel mode mpls traffic-eng
> tunnel destination 172.25.224.1
> tunnel mpls traffic-eng autoroute announce
> tunnel mpls traffic-eng path-option 5 explicit name PRIMARY-PATH
> tunnel mpls traffic-eng path-option 20 dynamic
> tunnel mpls traffic-eng fast-reroute
> end
> !
> interface Tunnel1051
> description nnhop protect tunne
> ip unnumbered Loopback0
> load-interval 30
> mpls ip
> tunnel mode mpls traffic-eng
> tunnel destination 172.25.224.9
> tunnel mpls traffic-eng autoroute announce
> tunnel mpls traffic-eng priority 5 5
> tunnel mpls traffic-eng path-option 1 explicit name BACKUP-PATH
> end
>
>
> *Before failure*
>
> R1#sh mpls traf fa da
> P2P Headend FRR information:
> Protected tunnel In-label Out intf/label FRR intf/label
> Status
> --------------------------- -------- -------------- --------------
> ------
> Tunnel101 Tun hd Fa0/0:31 Tu1051:31
> Ready
>
> *4 Seconds after failure:*
>
> R1#sh mpls traf fa da
> P2P Headend FRR information:
> Protected tunnel In-label Out intf/label FRR intf/label
> Status
> --------------------------- -------- -------------- --------------
> ------
> Tunnel101 Tun hd Fa0/0:31 Tu1051:31
> Active
>
> *After 30 seconds:* Tunnel is gone!!!
>
> R1#sh mpls traf fa da
> P2P Headend FRR information:
> Protected tunnel In-label Out intf/label FRR intf/label
> Status
> --------------------------- -------- -------------- --------------
> ------
>
>
>
> And yes backup command is confgiured under interface as you can see it
> works in nromal situation without failure!!!
>
> After restoring failure , tunnel will not come up!!!
>
> R1#sh mpls traf fa da
> P2P Headend FRR information:
> Protected tunnel In-label Out intf/label FRR intf/label
> Status
> --------------------------- -------- -------------- --------------
> ------
>
>
> I have to shut primary tunnel and backup and unshut them to get this back
> under FRR database.
>
> After I did above:
> R1#sh mpls tra fa da
>
> P2P Headend FRR information:
> Protected tunnel In-label Out intf/label FRR intf/label
> Status
> --------------------------- -------- -------------- --------------
> ------
> Tunnel101 Tun hd Fa0/0:37 Tu1051:37
> Ready
>
> What the hell is going on here?????
>
> Thanks!
>
> Jeremy
>
>
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Received on Wed Jul 04 2012 - 08:46:20 ART