Subject: draft-gan-fast-reroute

From: [email-masked]
Date: Thu, 11 Oct 2001 06:58:01 +0200

Hello,

I have a question on the RRO handling in <draft-gan-fast-reroute>.
 
       Node1 ====> Node2 ======> Node3 =====> Node4 ======> Egress
                      v                       ^ 
                      |                       | 
                      +-----------------------+ 

Notation: @(3-2) == IP address of node 3 on the link [node 3 - node 2].

Assume that the link between node 2 and node 3 fails. Then the detour 
[node 2 - node 4] is taking over. But what does node 2 then send in the 
RRO object of the RESV message to node 1: Does node 2 continue to send 
[@(2-1), @(3-2), @(4-3), @(egress-4)] or does node 2 send [@(2-1), @(detour between 4-2), @(egress-4)] or ...?

Thanks for any help you can provide,

        Francis.

---

From: Arthi Ayyangar <[email-masked]>
Date: Thu, 11 Oct 2001 18:40:03 -0400 (EDT)

Hi,

> [@(2-1), @(3-2), @(4-3), @(egress-4)] or does node 2 send [@(2-1),
> @(detour between 4-2), @(egress-4)] or ...? 
> 
---> It would send , [@(2-1), @(detour between 4-2), @(egress-4)] 
as the RRO in the Resv once the detour has taken over.

-arthi

---

From: Alia Atlas <[email-masked]>
Date: Thu, 11 Oct 2001 20:17:43 -0500

>as the RRO in the Resv once the detour has taken over.

No, the RRO in the RESV for the Primary LSP would not change.  Node 2 would
continue to send the same RRO as before the failure.

If you look at lsp-tunnel-09.txt, there is a "local protection in-use" flag
which could be set in the IPv4 subobject of the RRO, but the implementation
of draft-gan with which I am familiar doesn't do this.

Alia