arp cache

carl_townshend · ‎02-13-2009

Hi all, can anyone tell me, with arp cache on l3 devices, say the lifetime is so manyu hours, if I plug another device in before this time is up with a different IP address to mac binding than before, will it automatically clear the old binding straight away, or would you have to clear the arp cache, to be honest it has always worked straight away for me, but whats the Theory?

cheers

Carl

ccannon88567 · ‎02-13-2009

I think that you might be confusing the arp cache with the switching table? It would just add a new arp entry with a new IP & MAC.

carl_townshend · ‎02-13-2009

no, I know the switching table has a age timer, but the arp table also has a timer, I want to know how it updates on the fly, or do we have do wait until the lifetime of the arp entry has expired ?

ccannon88567 · ‎02-13-2009

The switch would automaticly update the entry. It wouldn't have 2 entrys with the same MAC and different IP's.

Mohamad Qayoom · ‎02-13-2009

The arp table gets updated on the fly.