Catalyst Switch: cam agingtime

[polm]

I need to move about 48 hosts from one switch to another. Both swithces are trunked and running STP with all hosts ports operating in the same VLAN.

Both switches are in the same rack, and moving the hosts from one to the other takes about 2 seconds.

Currently the aging time for CAM is 300 seconds.

If I move an active host from one switch to another, what is likely to happen to their network connectivity ?

 

[polm]

alright...apparently once the node is pulled the switch flushes the MAC. The new switch registers almost immediately, and being on same VLAN, the systems are moving fine and not seeing an outage longer than the amount of time it takes to move the cable.

 

[spidey07]

I believe a topology change notification (spanning-tree TCN) will force a flush of the cam table and set aging time to something like 30 seconds.

So when your port goes from forwarding to blocking, thats a TCN and flushes the table.

could be off base though, its been a while since I've been deep into operation of the cam table. It does help to understand it with things like HSRP, VRRP, and load balancing/failover.