What Trunking protocol to be enabled

raju · ‎10-15-2002

Hello All,

We have Catalyst 6509 (Layer3) switch as Backbone for our Network and it's already configured and running . We are planning to install Catalyst 4006 (Layer2 ) switches for end user connectivity . The connectivity between 6509 & 4006 will be through GBIC (SX) . I heard 4006 does not support isl trunking for uplink connectivity , only supports 802.1q . What trunking protocol should I use in 4006 side ?. Should I change the Trunking protocol for particular GBIC port on 6509 side which will be connected to 4006 or will it work on 6509 with ISL trunking and 4006 side 802.1q . pls clarify ...

Thanks in advance .

Raju.

thisisshanky · ‎10-15-2002

ISL or 802.1q are two different encapsulations used for Trunking. The encapsulations on either ends of the trunk has to be same.

Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus

Prashanth Krishnappa · ‎10-16-2002

I suggest that you use 802.1q as it is an IEEE standard and is compatible with any third party vendor switches as well

Frederic Vanderbecq · ‎10-16-2002

The catalyst 4000 with a SUP I or SUP II only supports dot1q trunking. Hence, you will have to configure the cat6k for dot1q as well on the ports going to the 4k.