09-16-2008 03:26 AM - edited 03-06-2019 01:24 AM
hi, got a message from 2 core switch 6509:
*Sep 16 18:54:38.141 gmt: IP-EIGRP(Default-IP-Routing-Table:109): Neighbor 10.100.17.2 not on common subnet for Vlan3
*Sep 16 18:54:38.141 gmt: IP-EIGRP(Default-IP-Routing-Table:109): Neighbor 10.100.16.50 not on common subnet for Vlan8
*Sep 16 18:54:38.141 gmt: IP-EIGRP(Default-IP-Routing-Table:109): Neighbor 10.100.16.50 not on common subnet for Vlan8
i thought the problem was because their interconnection was disconnected. i had them connected and i still get the message error on the both core switch.
i have used: clear ip eigrp neigh
clear ip route *
and log still persist.
any idea why?
the eigrp configuration was not changed
eigrp 109
10.0.0.0
the vrrp is ok
interface Vlan3 (cisco 6509)
ip address 10.100.22.54 255.255.255.0 secondary
ip address 10.100.16.50 255.255.255.0
ip helper-address 10.100.18.9
ip helper-address 10.100.18.13
no ip redirects
ip wccp 61 redirect in
vrrp 3 ip 10.100.16.254
vrrp 3 ip 10.100.22.254 secondary
vrrp 3 preempt delay minimum 5
vrrp 3 priority 150
end
interface Vlan3 (cisco 6509)
ip address 10.100.22.54 255.255.255.0 secondary
ip address 10.100.16.40 255.255.255.0
ip helper-address 10.100.18.9
ip helper-address 10.100.18.13
no ip redirects
ip wccp 61 redirect in
vrrp 3 ip 10.100.16.254
vrrp 3 ip 10.100.22.254 secondary
vrrp 3 preempt delay minimum 5
vrrp 3 priority 150
end
interface Vlan8
ip address 10.100.17.6 255.255.255.0
ip helper-address 10.100.18.9
ip helper-address 10.100.18.1
vrrp 8 ip 10.100.17.254
vrrp 8 preempt delay minimum 5
end
09-16-2008 03:37 AM
This has little to do with vrrp. You get this message when two connected interfaces running eigrp are using different ip subnets.
The conflicting device is identified as the neighbor and the message also tells you the vlan where the mismatch is detected.
Looking at the logs, my conclusion is that the ip adresses for vlan3 and vlan8 are configured in opposite order as on the device shown.
regards,
Leo
09-16-2008 04:38 AM
Eduard
Perhaps Leo is correct that it is a configuration error with addresses in opposite order. But I wonder in looking at these messages:
*Sep 16 18:54:38.141 gmt: IP-EIGRP(Default-IP-Routing-Table:109): Neighbor 10.100.17.2 not on common subnet for Vlan3
*Sep 16 18:54:38.141 gmt: IP-EIGRP(Default-IP-Routing-Table:109): Neighbor 10.100.16.50 not on common subnet for Vlan8
*Sep 16 18:54:38.141 gmt: IP-EIGRP(Default-IP-Routing-Table:109): Neighbor 10.100.16.50 not on common subnet for Vlan8
and noticing that VLAN 3 is complaining about an address belonging to VLAN 8 and that VLAN 8 is complaining about an address in VLAN 3, then it makes me wonder if someone has changed a connection so that VLAN 3 and VLAN 8 are now connected in some manner. That would be consistent with your statement that the configuration was not changed. I wonder if the output of show cdp neighbor and of show vlan 3 and show vlan 8 might help us find the issue.
HTH
Rick
09-16-2008 05:19 AM
hi rick, only the int giga 5/2 between the core switch were disconnected but were able to plug it back.
i shutdown the vlan interface of vlan 8 and 3 on core switch 2 and the logs were gone on coreswitch 2, however, on core switch 1 the logs persist.
i even shutdown both vlan and activate it back, but to no avail the log persist
09-16-2008 05:46 AM
Eduard
If the errors stop on switch 2 when you shut down both VLANs, do the errors stop if you shut down only a single VLAN?
I continue to wonder if the issue is that someone has connected something that is interconnecting VLAN 3 and VLAN 8. Perhaps a hub or perhaps a switch with an access port in VLAN 3 and another access port in VLAN 8. Can you post the output of show cdp neighbor as a starting point to investigate this?
HTH
Rick
09-16-2008 06:03 AM
09-16-2008 09:06 AM
Eduard
Thank you for the output of show cdp neighbor. Would you also post the output of show vlan on both 6509 and the configuration of the interfaces gig 2/0/11, 2/0/12, 3/0/23, and 3/0/24 from the 3750.
HTH
Rick
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