EIGRP - Change metric per subnet and per neighbor.

[morabusa]

I am trying to make work something ehich is probably not possible with EIGRP but I would like to confirm it befere deciding to use a different routing protocol. I have an escenario where I have the following devices:

1- Layer 3 CoreSwitch with EIGRP running in the vlan 10.

2- ISP1 Router MPLS with EIGRP running in the vlan 10.

3- ISP2 Router MPLS with EIGRP running in the vlan 10.

(As you can see, the 3 devices are connected in the same vlan/subnet and all of them are EIGRP neighbors)

Routes advertised by ISP1 have better EIGRP metric and this is ok but I would need to modify the metric in the CoreSwitch, to prefer one subnet advertised from ISP2.

I know how to locally modify metrics in EIGRP per neighbor, for example:

L3SW(config)#access-list 22 permit 192.168.30.0
L3SW(config)#router eigrp 55
L3SW(config-router)#offset-list 22 in 10000 vlan10
L3SW(config-router)#exit
L3SW(config)#end

The problem I have is that both neighbors are known through the same SVI (int vlan 10), and I am not sure if there is anything I could do just with EIGRP to fix this (I am thinking about using static routes with a track but I would prefer to achieve this just with EIGRP). Is this possible to do?

[morabusa]

Hello Bejanmin,

I tried this but it did not work because the following command was not supported in Nexus (at least not with its current NX-OS version):

router eigrp 55

 distribute-list route-map SET_METRIC in

So I used this configuration and it works pretty well:

router eigrp 55
 address-family ipv4 unicast
  table-map Modify-AD

route-map Modify-AD permit 10
 match ip route-source prefix-list route-source-IP
 match ip address prefix-list route-to-modify
 set distance 91

ip prefix-list route-source-IP seq 5 permit 10.10.10.1/32

ip prefix-list route-to-modify seq 5 permit 192.168.30.0/24

Best regards and thanks for the help!

[Richard Burts]

I really like this suggestion. I believe it is much more straight forward to modify the metric that it is to try to modify the AD. A well deserved +5 for this excellent suggestion.