topic Re: 4000 - Port Address Table in Switches, Hubs, and Modems

4000 - Port Address Table

Carl Morss — Wed, 25 Jul 2007 04:48:37 GMT

Ive noticed that my Procurve 4000's Port Address Table for a given Port is blank, then after a few seconds displays the MAC address of the connecting PC for an arbitary amount of time before going blank again - the event log doesnt show that the port is going off-line, nor are their any drops or errors.....

the MAC age interval has been left on the default 5 mins - but this shouldnt have any bearing on this anyway as traffic is still passing accross the port from an always on PC.

does anyone have any ideas why this is happening - if its normal - if not what can i do to stop it.

Re: 4000 - Port Address Table

Matt Hobbs — Wed, 25 Jul 2007 17:38:53 GMT

If you have spanning-tree enabled and there are topology changes occurring, that will cause mac-addresses to age out in about 30 seconds or so.

Re: 4000 - Port Address Table

Carl Morss — Thu, 26 Jul 2007 01:10:50 GMT

Interesting - yes we run spanning tree, but i thought topology changes only happened when a switch went offline, and the root path/cost changed because of that.... the problem ive been observing seems to happen every few minutes.

i appreciate your input thanks