«

Hi,
we are using EIGRP as our enterprise routing protocol. Our network is
3-tier, so small remote locations and connected to regional offices. And
regional offices are then connected to central office.
Current design is that regional office has all routes of all remote offices
that are connected to that particular regional office. And regional office
sends one summarized route that represent routes for all remote locations.
So central locations, besides its own routes, has only summarized routes of
all regional offices.
But, backup facility for all locations is located on central location. So,
after some remote office loose conenction to its regional office, it dials
to AS5350 located in central location. When it connects, it send its own
routes via EIGRP. After that, central location routers has summarized route
for regional offices and of course specific routes for dialin locations
(whether on backup or only use isdn dialin).
Problem is, when primary link goes online for that specific location it
starts to send all outbound traffic thru its primary link. Since dialer
interface is still up (because of timer, usig floating static routes),
central location still has its specific route toward that location and
returning traffic is still sent thru isdn connection. And we have asymetric
routing. If I define on remote location that only outgoing traffic is
interesting (as opposed to both), that after some time, remote location
drops dialer, and eigrp route dissapears from central location, and central
location again uses summarized route to send all traffic to regional office.
Would someone do this some other way ?
Another solution would be that central location (7200 and AS5350 routers)
has all specific routes (regional offices not doing summarizazion). But
central routers are summarizing back to regional offices with one default
route, so regional offices still have small routing table.
What is the recommended way ?
thanks for the tips,
mike

[kakurenaide]

As long as your backup line is advertising a route to that specific network, EIGRP will always favor that route to a summary because the best path is the path with the best cost of the longest prefix match. As long as the regional offices are submitting summary routes, the backup will be preferred until disconnect. You can try using the dialer-watch mechanism (IOS 11.3T) to bring up the dialer when the route to the central office goes down. This function also has the ability to tear down the interface after the main route has been restored. See

http://www.cisco.com/en/US/products/...0800ca528.html

Hope this helps!