We have a border router, a 7206VXR running 12.3(11)T3 which gateways our entire class B network into a local area network feeding 10 interior routers. OSPF is used internally, and the gateway router is seeing all of the appropriate next-hops.
The gateway router has decided that it needs to maintain, and regularly ARP for the entire class B on the interior network. They are not 'broadcast' ARP's, but rather, directed at the appropriate next-hop ethernet address.
The gateway router has been running this release for about 3 weeks. I can't say for sure, but I believe this behavior just started this weekend. If it had started earlier, it surely would have been noticed, since it does disrupt the monitoring of our internal wireless lan when the ARP storm hits that network every 3 minutes. There have been no significant changes to this router (except for the OS upgrade) in over a year.
Note that this is a continuous action, not sporadic due to some outside scan.
Anyone have an idea what may be causing this, or what I can do to stop it?
Roger snipped-for-privacy@gmail.com