[j-nsp] IS-IS Badness with JunOS

[Mark Tinka]

On Tuesday 07 April 2009 04:03:39 am Piotr Marecki wrote:

> Are you advertising RSVP LSP as p2p links in ISIS ? ( aka
> forwarding-adjacency feature in IOS ) and/or you are
> using TE shortcuts ?

Neither.

On the Cisco side, we're using the Autoroute feature (tunnel 
mpls traffic-eng autoroute announce). We find it's less 
complicated than Forwarding Adjacencies, and does the job 
quite sweetly.

On the Juniper side, given that we only need to traffic 
engineer data toward only three destinations on the other 
side, we found pointing static routes into the traffic-
engineered LSP's (lsp-next-hop) to be quite simple and 
predictable. We've been lab'ing IGP Shortcuts for the 
Juniper side, but we've found we need to have a couple of 
trade-offs in other areas, so we're still waiting to 
reliably deploy that.

LDP is tunneled within RSVP on both sides.

We've had cases where the circuit between the traffic-
engineered routers fails for regular reasons that circuits 
fail, and MPLS LSP's + RSVP signaling along the failed path 
is nicely torn down and traffic immediately re-routed to the 
backup path (ECMP); and the paths come back up nicely when 
service to the failed link is restored - no impact to 
customer traffic. So we've not seen any "stuck" 
relationship, so to speak, between RSVP and IS-IS before.

The only difference here is we, by hand, restarted RSVP.

> It looks indeed scary, but theoretically FA has big
> potential of doing bad thing...

Indeed.

We're trying to stay away from FA's. They would add 
complexity in our case.

> Sorry for not providing answers, but just giving more
> questions :(

Appreciate the input.

JTAC are also checking it out. Will let you know if they 
find anything interesting.

Cheers,

Mark.
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