Re: Next question...

[Iljitsch van Beijnum <iljitsch@muada.com>]

On Sun, 8 Dec 2002, Eliot Lear wrote:

> > |   I would still like some hint from the host to the border
> > |   router that the
> > |   current connection isn't working.

> > Not an unreasonable request.

> At first blush this may seem like a reasonable request, but there are so
> many reasons why a remote host would not respond that it would be
> impossible for the routing system to trust the local host with such
> requests.  For instance, perhaps the reason the remote host isn't
> responding is because the remote application has not properly
> authenticated the local user.  Another reason is that the remote host is
> down or misconfigured.

I'm not sure if I understand what you're getting at the the issue of
trust.

But there is another problem: a site has many hosts. As you say, a host
can be down, but that doesn't mean a neighboring host is also down. So
if the SBR is going to reroute the traffic for a host a the source's
request, this must be done on a per-destination host basis, or the
source must request the alternate path in each individual packet, for
instance with a diffserv code point. Both of these are at least somewhat
problematic.

All of this makes me feel that doing this at the source host in the
first place might be a better solution in many cases.