[nsp] Two Routes to destination - failover

[Paul Stewart]

Thanks Kevin and everyone else who replied...

I'll take a look at this idea.. Sounds pretty well what we're after...

Paul


-----Original Message-----
From: Kevin Graham [mailto:mahargk at gmail.com] 
Sent: Monday, July 12, 2004 11:01 PM
To: Paul Stewart
Cc: cisco-nsp at puck.nether.net
Subject: Re: [nsp] Two Routes to destination - failover


On Mon, 12 Jul 2004 21:02:37 -0400, Paul Stewart <pauls at nexicom.net> wrote:

> We currently have a remote site that is working fine.  For redundency 
> we would like to take a separate physical route to this location using 
> wireless and make this new connection the "primary" connection and the 
> existing connection a "backup" connection.

route metrics aren't going to work in this case, since I'm guessing the link
state on the router's interface for the wireless connection won't track the
actual availability. A routing protocol is the easiest, most straightforward
option.

What would also work (if you can run 12.3T) is "Reliable Static Routing
Backup Using Object Tracking":

http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123
limit/123x/123xe/dbackupx.htm

The one big plus to this approach is by using SAA probes, you could
accomodate for things like variable link quality over the wireless link. The
main caveat would be the potential for assymetry, though even if you
couldn't prevent this just make sure you're  aware of the impications.