Cisco Support Community
Community Member

EIGRP Convergence Issue - Limiting scope of query

Recently, I had come out a design (c/w Cisco presales) for my new customer using Cisco router with EIGRP. My customer has some background with Cisco router which has the experience of the EIGRP fail their existing network when one of their data center Cisco switch goes down and this cause the local and remote router EIGRP start sending the query for recalculating (convergence)the alternate path. This believe is in SIA state. My customer network now starting grow to about 50 routers and believe much more in the later. We are worry the above problem happen and this bring me to ask your expertise to consults.

I have go through the routing book and the best way to limit the scope of the query is to implement the summarization or filtering. My customer network are setup by using the redundant link resign and current design is something different from the manual which recommended by Cisco presales in the early stage. We are using the summary at branch and route filtering at regional routers. It is different from book which regional routers should apply the summarization on all outbound interfaces to remote branch and filters were installed at the remote routers to limit their advertisments.

My doubts is when one of the segment at regional goes down, the router will send the queries to all the interfaces and has to wait for all the queries reply. Will this query send to all branch with the above setup ? or must we configured all the regional routers outbound interfaces by using ip summary eigrp with include all the segment (regional has 5 local segments then is it 5 entry of ip summary eigrp ?) and by then only will really reduces the convergence traffic caused by the redundant topology. Please consults and thank in advance. Your reply is highly appreciated.

For Reference only:

The current setup for Customer routers are

1) using route filtering (distribute-list out serial = apply the specific route to the particular branches)at regional routers to specific route to branch routers (this to limit branch router can not access to another branch router)

2) branch router serial interface will configured with ip summary eigrp (manual) at the serial interface (both link) that directly connected to regional routers.


Re: EIGRP Convergence Issue - Limiting scope of query

CreatePlease to create content