[c-nsp] Weird 6PE problem on ASR1k

Thu Oct 7 15:34:07 EDT 2010

Okay that¹s good to know.

Thanks for the help

Kind regards,
Sigurbjörn

From: Harold Ritter <hritter at cisco.com>
Date: Thu, 7 Oct 2010 13:12:34 -0400
To: "Sigurbjörn B. Lárusson" <sigurbjornl at vodafone.is>
Cc: <cisco-nsp at puck.nether.net>
Subject: Re: [c-nsp] Weird 6PE problem on ASR1k

Hi Sigurbjörn,

I believe the behavior has been explicitly changed. You would see the same
behavior on the 7200 if you used SRD4. So going forward, you should
configure the "set mpls-label" whenever a route-map is used.

Regards

Le 2010-10-07 à 12:13, Sigurbjörn Birkir Lárusson a écrit :

> That worked!
> 
> At least that¹s a usable workaround until this is fixed (I¹m assuming this is
> a bug, might be wrong though)
> 
> Kind regards,
> Sigurbjörn B. Lárusson
> 
> 
> From: Harold Ritter <hritter at cisco.com <x-msg://88/hritter@cisco.com> >
> Date: Thu, 7 Oct 2010 11:59:51 -0400
> To: "Sigurbjörn B. Lárusson" <sigurbjornl at vodafone.is
> <x-msg://88/sigurbjornl@vodafone.is> >
> Cc: <cisco-nsp at puck.nether.net <x-msg://88/cisco-nsp@puck.nether.net> >
> Subject: Re: [c-nsp] Weird 6PE problem on ASR1k
> 
> Hi Sigurbjörn,
> 
> Try configuring "set mpls-label" in the route-map.
> 
> Regards
> 
> Le 2010-10-07 à 06:30, Sigurbjörn Birkir Lárusson a écrit :
> 
>> I'm having a weird issue with BGP peering in address-family ipv6 unicast
>> from a ASR1002-F running 3.1.1S (15.0(1)S) to a 7200 running 12.2(33)SRD3
>> and another ASR1002-F running the same software, that I have setup in a lab.
>> 
>> When a route-map (regardless of the contents, even route-map XXX permit 10
>> doesn't work) is applied on the outbound to the ipv6 neighbor of the ASR
>> with 3.1.1S, it seems to stop sending labels for the IPv6 prefixes, the
>> labels for show bgp ipv6 unicast labels show nolabel/nolabel for the routes
>> in question and debugging ldp doesn't show the labels being sent.
>> 
>> The result of this is that the route shows up on the 7200 in BGP for ipv6
>> unicast, but the next hop is inaccessible, and the route doesn't go into the
>> ipv6 table obviously.
>> 
>> As soon as I remove the outgoing route-map and soft reset the session on
>> outbound, the next-hop is no longer inaccesible and the labels are there if
>> I do a show bgp ipv6 unicast labels.
>> 
>> If I re-apply the route-map and soft reset the session on outbound again,
>> the BGP session sometimes (but not always) resets with the following error:
>> 
>> *Oct  7 02:36:29.970: %BGP-3-NOTIFICATION: received from neighbor
>> 192.168.1.3 3/10 (illegal network) 1 bytes 98
>> 
>> And when it comes back up, the labels have disappeared and the problem has
>> resurfaced.  Even if the session does not reset, and no error is shown, it
>> the symptons are same, the labels are not sent.
>> 
>> This seems to be an issue with the ASR not the 7200, the same symptom is
>> seen on a ipv6 peering to another ASR1002-F when a outgoing route-map is
>> applied to the bgp neighbor.
>> 
>> Note that this only seems to affect IPv6 unicast, I'm also testing vpnv4 and
>> vpnv6 (using 6VPE) all of which work without issues, with the same
>> peer-policy inherited (and therefore the same route-maps).
>> 
>> The first release that supports 6PE according to the release notes (unless I
>> misunderstood them) is 3.1.0S so there is no going back to 2.X, I could try
>> 3.1.0S instead of 3.1.1S but that seems somewhat counter productive.
>> 
>> Anyone seen this before, or have any suggestion on how I could get around
>> this?  
>> 
>> Kind regards,
>> --
>> Sigurbjörn B. Lárusson
>> 
>> 
>> 
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> 
> 
> Harold Ritter
> Directeur Technique/Technical Leader
> Advanced Services Central Engineering
> CCIE 4168 (R&S, SP)harold at cisco.com <x-msg://88/harold@cisco.com>
> <mailto:harold at cisco.com>
> Téléphone: 514 847 6856Les Systèmes Cisco
> 1800 McGill College
> Suite 700
> Montréal, Québec H3A 3J6
> Canada 
> 
> 
>  
> 
> 

Harold Ritter
Directeur Technique/Technical Leader
Advanced Services Central Engineering
CCIE 4168 (R&S, SP)harold at cisco.com <mailto:harold at cisco.com>
Téléphone: 514 847 6856Les Systèmes Cisco
1800 McGill College
Suite 700
Montréal, Québec H3A 3J6
Canada 