I am working at a client site today on a routing issue. I am currently working on an issue where a 3750 switch running EIGRP will not update its neighbor router when a network statement is added to the eigrp instance.
The neighbor is a 3825 router.
Both the switch and the router have a common network which is 192.168.36.0/24.
Both the switch and the router are in a neighbor adjacency.
Both boxes have "no auto-summ" in the routing configuration instance.
I can run debugs on both routers (debug eigrp packets) and then I can watch queries and updates when I issue "auto-summ" or "no auto-summ". Also I see a "graceful restart" for the peers when this is done.
I had an expectation that when I added the network (this is just an arbitrary network for testing, which is 172.16.69.0/24). I wanted to watch this network being sent in an update to the neighbor router.
When I add the above mentioned network, there are no updates packets sent from the 3750 to the 3845. I have not had success to this point trying to resolve. I have followed the Cisco document "Troubleshooting EIGRP Flow Chart", but have exhausted all it has to offer and now it is at the point where it is telling me to contact TAC.
I wanted to post this first. I am sure this is something simple I am missing. I appreciate any and all help.
First of all I have to explain why I do think that you need to filter :
when you create a summary route on the eigrp , even though you are creating it on the interface, the eigrp process will have this route in the topology and it will advertise the summary to any eigrp neighour.
So if you want to make two summaries ( 1 client routes and 1 BP routes ) we have to prevent this routes going to BP ( the BP summary ) and to client ( the Clinet summary ).
Furthermore you will advertise a summary route of the client to BP network, I do not know if the BP network filters the advertisements but there are some chances that this summary will reach your 3750 HQ switch and then goes to the client.
Where you have indicated that I should "filter OUT - on the MPLS interface the CLIENT summary... Do I use a distribute list with a deny statement to accomplish this?
Yes, on 3750 DR, yes and set the distribute list on the client interface ( or SVI ). For example
distribute-list CLIENT-OUT out fa1/0/1
distribute-list CLIENT-OUT out Vlan 5
ip access-l stan CLIENT-OUT
The client's summary should be created on the interface toward the BP.
Where you have indicated that I should "filter OUT - on the BP interface the BP summary.... We do not have access to the BP router, so I would only be able to accomplish this by working with the BP. I know this isnt a quesiton per say, but did want to document that with you.
No, it's the same as for the client summary.
ip summary-address eigrp #
ip access-l stan BP-OUT
router eigrp #
distribute-list BP-OUT out
Now comes to my mind that you have to filter this BP-summary also on HQ 3750 , coming from MPLS. (!!!)
Where you have indicated that I should "filter IN - on the BP interface the CLIENT summary... Do I use a distribute list with a permit statement to accomplish this?
No. On HQ 3750 you will have 2 filters related to the summary made on DR:
access-list stan BP-IN
access-list stan CLIENT-IN
router eigrp #
distribute-list CLIENT-IN in
distribute-list BP-IN in
Because you do not want the BP summary that was created on DR and you do not want the client summary also made by the DR.
The HQ 3750 is currently not configured as a stub.
That's good ! Then on HQ 3750 will only filter the summaries made by the DR 3750
Routing Protocol is "eigrp 13"
Having stub will not stop you advertising conncted subnets.
Kevin tried to advertise something that did not exist in the routing table.