[50824] in North American Network Operators' Group
Re: endpoint liveness (RE: Do ATM-based Exchange Points make sensean
daemon@ATHENA.MIT.EDU (Petri Helenius)
Sat Aug 10 11:05:20 2002
Date: Sat, 10 Aug 2002 18:02:40 +0300
From: Petri Helenius <pete@he.iki.fi>
To: Mike Hughes <mike@smashing.net>
Cc: nanog@merit.edu
Errors-To: owner-nanog-outgoing@merit.edu
Mike Hughes wrote:
> But, how does that work when you may be delivering multiple q-tags on a
> single GigE port (for example)? If only one tag is affected, you don't
> want to drop link, right?
>
> So, we're back to detection at layer 3, can I ping it, do I have
> adjacency, etc.
>
> Some sort of lower-level heartbeat (maybe like OAM), not dependent on IP
> reachability, would be a bonus - and it's probably low in the tax stakes,
> if it can be made simple enough.
>
I think pseudowire liveness (in case of ethernet pseudowires which are
by nature multipoint and multi-vlan) does not really make sense but as you
conclude L3 liveness does. Obviously one can repeat the exercise for everything
that needs liveness but it would make more sense to have a generic way to
determine L3 reachability in a robust manner.
Pete
