[c-nsp] Thoughts on 3 site failover

[Tuc at T-B-O-H.NET]

Hi,

	I have a situation where I have the following :

T1-SITE_A-----SITE_B

	At Site A is a 2851. Site B uses wireless backhaul
to Site A for its connectivity. All is good. Because of
how its configured, Site B looks like just an extended part
of Site A, not any sort of routing, etc.

	The next step (This week) is going to be :

T1-SITE_A-----SITE_B-------SITE_C

	All we'll do is wireless backhaul Site C to Site B,
and then back to Site A. Should be all good. Sites B and C
still look like a single "LAN SEGMENT" if you will.

	The final step (Next month) is going to be :


T1-SITE_A-----SITE_B-------SITE_C-T1

	At that point a 2851 will be put at Site C also.

	As a default all Site A traffic will go out the
Site A T1, and all Site C traffic will go out the Site C
T1.

	I'm trying to think the best ways to go about
the whole set of scenerios like :

*	Site B goes out Site A unless it is full then try
to funnel rest to Site C

*	If Site A T1 goes down, shove everything out Site
C.

*	If Site C T1 goes down, shove everything out Site 
B.

	SO.... I was trying to get the owner to put a 2851
at Site B and do it with some BGP magic (Along with a 
Zebra box or other box "helping" trying to do the load
balancing). It doesn't look like he will, so I might have
to do it some other way, like maybe HSRP?

		Thanks, Tuc/TBOH