Cam Age Timer

[tylerc]

When looking at the CAM age time on a CAT5505 with software version 4.5(13a) the age out time is changing from 300 secs to 15secs intermitantly across all vlan's, Is this correct and if so what causes the change. If not what is the remedy.

[Prashanth Krishnappa]

Spanning tree TCN's causes this

http://www.cisco.com/warp/public/473/17.html

Make sure you have enabled Spanning-tree portfast on all ports which are directly connected to end devices. Check to see if you have any links going up and down

[dtaft]

This is the default action when a topology change occurs. Basically the 5 min default aging timer may be problem after a topology change occurs (link down etc), so as soon as a switch detects the change the event is advertised to the whole network. At this the switch reduces the aging timer to 15 seconds.

Checking the portfast and links should identify any problems in the bridged topology