CAM table flush timer for OOB NAC

hemant_bharati2004 · ‎04-08-2009

Please let me know what is the advantge of inceasing the CAM table flush timer on switches , while implementing NAC OOB.

htarra · ‎04-15-2009

When you are Configuring SNMP setting on the switch to send traps to the NAC Manager which facilitates the tracking of port and CAM table status you will be increasing the default CAM table entry flush timer to 1 hour as per Cisco best practice recommendations for NAC OoB using the following command:

mac-address-table aging-time 3600

hemant_bharati2004 · ‎04-16-2009

Thanks but still didnt got why to increase the CAM table aging time?

michael_dean · ‎04-16-2009

My best guess would be to cut down on the amount of traffic being sent to the CAM.

In OOB, when a new MAC is seen on the port, it is sent to the CAM to determine if it is in the Certified Device List (or a filter) or if it needs to be postured (manually clearing the MAC on a port also triggers this).

Changing the default cuts down on these events.

Mike