cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
340
Views
0
Helpful
1
Replies

bogus arp table contents

Tod Larson
Participant
Participant

My 2821 router has an arp table with the wrong ip to Mac mappings. The impact is that I can reach any host in the 10.1.1.1 subnet. I can reach hosts in the 192.168.35.0 just fine.

Int g0/0

Ip address 10.1.1.1 255.255.255.0

Ip address 192.168.35.2 255.255.255.0 secondary

The router arp table has this info

10.1.1.1 Mac d43d

192.168.35.252 32da

192.168.35.2 Mac bb33

192.168.35.1 Mac 78ab

10.1.1.2 Mac 78ab

10.1.1.3 Mac 78ab

10.1.1.4 Mac 78ab

10.1.1.5 Mac 78ab

...

10.1.1.21 Mac 78ab

Any ideas what is going on? It is as if the 192.168.35.1 device is answering all arp requests as a proxy arp or something.

Clear arp-cache nor clear ip arp on my 2821 have any affect.

1 Reply 1

Tod Larson
Participant
Participant

I ended up working around the problem by creating a separate vlan for both subnets and not having secondary addressing. Now things seem to work as expected.

Sent from Cisco Technical Support iPad App

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: