Trunking on an interface

AgJames86 · ‎02-23-2009

Good day!

I have recently discovered a peculiar thing about enabling/disabling trunking on a switch interface.

In a topology for inter-Router VLAN trunking, after disabling trunking on an interface connectivity between the devices on two different VLANs remains.

After about 5-7 minutes connectivity fails as it basically should be after disabling trunking mode. However for the first 5-7 minutes, I am able to ping and reach the machine on the other VLAN.

So my question: is there any timeout for trunking on an interface in the cisco switches or it is cashed somewhere/somehow?

I couldn't find the answer for that.

Thank you very much in advance!

Igor

milan.kulik · ‎02-23-2009

Hi,

looks to me like the switch forwarding address table keeping the VLAN/MAC pair for the destination devices.

After forwarding table age-out (5 minutes by default), you are losing the connectivity.

You should be able to check by issuing

sh mac-address-table

command.

BR,

Milan