Filtering Outbound Routes on EIGRP Based on Neighbor

[Javier Zamora]

I am looking to confirm if there is a way I can filter the routes I send out on neighbor by neighbor basis. My question comes from the fact I am running EIGRP, have multiple neighbors on a single interface (Tunnel interface on hub for DMVPN) and not all the neighbors should receive the same set of routes. Here is an example:

Hub1#sh ip eigrp n
IP-EIGRP neighbors for process 90
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
2 192.168.1.4 Tu0 12 00:00:07 44 396 0 3
1 192.168.1.3 Tu0 27 00:35:54 36 216 0 3
0 192.168.1.2 Tu0 12 00:36:00 51 306 0 3

I want to be able to distribute one set of routes to 192.168.1.4 and a different one to the other two neighbors. Is this possible? I know with distribute-list you can only specify direction and interface. Any other method?

Thanks

[Philip D'Ath]

Are the routers dynamically learned, or statically configured?

You can do "filtering" by interface?  Would that work for you, using the same filter for everything on the same tunnel interface?

[Philip D'Ath]

For example, to filter out all EIGRP routes except the default route going out Tunnel 1:

interface Tunnel1
  ip summary-address eigrp <ASN> 0.0.0.0 0.0.0.0

[Philip D'Ath]

I've had a bit more of a think about this one.  I think what you are going to need to do is filtering the routes as they are received by the remote parties, rather than change what you are sending.

Check out the use of inbound distribution lists.

http://www.cisco.com/c/en/us/td/docs/ios/12_2/iproute/command/reference/fiprrp_r/1rfeigrp.html#wp1030091

[Javier Zamora]

The neighbors are dynamic, I am looking more of a filter per neighbor, meaning some way of sending a set of routes to a neighbor and a different set to another. 

[Carlos Villagran]

Hi!

I would use the distribute-list with a route-map to advertise routes tagged with x and y and neighbors would run distribute-list as in and filter tag x or y.

For example, 

Sender router:

Standard IP access list TO1
10 permit 1.1.1.1 (6 matches)
20 permit 3.3.3.3 (6 matches)
Standard IP access list TO2
10 permit 2.2.2.2 (6 matches)

route-map lol permit 5
match ip address TO1
set tag 100
route-map lol permit 10
match ip address TO2
set tag 200

router eigrp 10
distribute-list route-map lol out

Receiver router 1:

route-map lol deny 5
match tag 200
route-map lol permit 10

 distribute-list route-map lol in 

Receiver router 2:

route-map lol deny 5
match tag 100
route-map lol permit 10

 distribute-list route-map lol in 

Please refer to the following link for the details of tagging routes:

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_eigrp/configuration/xe-3s/ire-xe-3s-book/ire-en-rou-tags.html#GUID-E38D91E9-4192-4507-8C1E-623DABF03618

Hope it helps, best regards!

JC