Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

bogus arp table contents

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.

  • LAN Switching and Routing
1 REPLY
New Member

Re: bogus arp table contents

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

251
Views
0
Helpful
1
Replies
This widget could not be displayed.