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What Trunking protocol to be enabled

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 .



Re: What Trunking protocol to be enabled

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

Cisco Employee

Re: What Trunking protocol to be enabled

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

Cisco Employee

Re: What Trunking protocol to be enabled

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.

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