csm arp cache timeout issues

[daniel]

Hello all.

The arp cache timeout of the csm is normally 4 hours.

Now if we want to replace one of our servers we would need to wait 4 hours before the new servers mac address is learned if we keep the old ip-address.

I know we can manually flush one entry from the arp cache but is there a way for the csm to find out sooner if the mac address has changed?

I also know we can make the time shorter before the cache expires but what would be the consequences if we would put the timer to lets say 1000 seconds?

Would we then be flooding our network with arp requests all the time?

[Gilles Dufour]

the 4 hours timeout is for learned entries.

These are devices that we learn [they are not configured as a real or gateway] - ie client.

For servers, the same will send arp request every 30sec. So, the CSM should learn the new address in less than 30 sec.

This is configurable as a variable.

gdufour-cat6k-2#sho mod csm 3 var

variable value

----------------------------------------------------------------

ARP_INTERVAL 30

ARP_RETRIES 3

Gilles.