IP-EIGRP: Neighbor 192.168.40.3 not on common subnet for Ethernet0

[mojo2002]

IP-EIGRP: Neighbor 192.168.40.3 not on common subnet for Ethernet0

I get this message when I switch term mon on, its on a 1720 router, here is the config.

version 12.2
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname router
!

!
ip subnet-zero
no ip domain-lookup
!
!
interface Ethernet0
ip address 192.168.41.27 255.255.255.0
full-duplex
!
interface FastEthernet0
ip address 192.168.8.1 255.255.255.0
speed auto
full-duplex
no cdp enable
!
router eigrp 55
network 192.168.8.0
network 192.168.41.0
auto-summary
no eigrp log-neighbor-changes
!
ip default-gateway 192.168.41.1
ip classless
ip route 0.0.0.0 0.0.0.0 Ethernet0
ip route 192.168.40.0 255.255.255.0 Ethernet0
no ip http server

The router is conected via a 10mb les circuit up to our main switch.

We operate two subnets on the main site 192.168.40.0 and 41.0, these are router between via our internal router.

Can Anyone spread some light?

 

[philmcgarry]

can you post the sh ip eigrp topology, and sh ip eigrp neighbors,sh ip route and sh ip protocols.

philmcgarry
ccie

 

[ForceMajuere]

Hi mojo2002,

Why do you want to run a routing protocol (EIGRP) when you've already got a static route?

The cause of your "IP-EIGRP: Neighbor 192.168.40.3 not on common subnet for Ethernet0" error is probably because your neighbor router is in a different subnet.

Check both routers are in the same subnet.

Then check that you have a neighbour relationship (SHOW IP EIGRP NEIGHBORS)

Then try adding this command to your EIGRP config;

no EIGRP log-neighbor-warnings

Example:-

router eigrp 55
network 192.168.8.0
network 192.168.41.0
auto-summary
no eigrp log-neighbor-changes
no EIGRP log-neighbor-warnings

This will stop you seeing the error.

Failing that you could refer to the Cisco website;

http://www.cisco.com/warp/public/103/trouble_eigrp.html

HTH

Force Majuere

 

[orb1tals]

Your router is seeing eigrp multicasts from 192.168.40.3 and since you are using ethernet which is multiaccess, your router is complaining that it is seeing eigrp adverts from a router not on its subnet. Although you can use ethernet in this way, eigrp, because it forms neighbor relationships expects to see neighbors on a subnet for which it is running eigrp.
It is interesting that you are seeing this message on ethernet0 and you have a static route to that subnet (192.168.40.0) via e0. If this is the desired design then this suggests that there either isn't a router between the 2 subnets (192.168.40.0 & 192.168.41.0) or that the remote router's ethernet interface has an incorrectly configured subnet address.

Force Majuere, it is possible that this router is learning Eigrp routes off another router on its fastethernet subnet (192.168.8.0)thats why he has static default routes and eigrp at the same time. The static route may provide an alternative route to those subnets in the event it no longer hears of them via Eigro on Fa0. Without seeing the routing table, difficult to be sure.