Adjusting Arp cache timeout on rotuer interface

mbroberson1 · ‎03-31-2009

If you have (failover) senario where adjusting the arp cache timeout on a router interface (from default of 4 hours) could prove beneficial is there a recommened minimal threshold to not go below in seconds?

Thanks,

Brandon

royalblues · ‎03-31-2009

It is generally recommnded to have the arp timeout same as that of the mac-address aging time (300 sec). It can be used as a threshold

Are you having unicast flooding in your network to adjust the arp timers?

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094afd.shtml#t8

Narayan

mbroberson1 · ‎03-31-2009

There is a setup with a vendor that when they failover to a backup link sometimes we have to manually clear arp on our primary router.

I wonder if the "arp probe interval" under the specific interface where arp needs to be cleared would be a good choice?

Thanks