Re: IOS image does not support ISL encapsulation.

speculor_cisco · ‎01-26-2011

I have bought a new 2960 switch. The IOS image does not support ISL encapsulation. As I would like to test some STP features, which IOS image does support ISL encapsulation? And how can I get it? Thanks.

jonathanaxford · ‎01-26-2011

Hi there,

I have a feeling that the Cisco 2960 series of switches only supports 802.1Q truking, not Ciscos ISL so this can't be fixed by an IOS upgrade.

Is there a reason you muct use ISL instead of 802.1Q trunking?

Many thanks

Jonathan

speculor_cisco · ‎01-26-2011

Hello Jonathan and thanks for your answer.

I would like to test the difference between "pure" PVST and PVST+.

As I will buy a 3560 switch too, do you know if this series supports it?

cadet alain · ‎01-26-2011

Yes,

the 3560 supports ISL.

Regards.

Alain.

Don't forget to rate helpful posts.

Leo Laohoo · ‎01-26-2011

I have bought a new 2960 switch. The IOS image does not support ISL encapsulation.

2960/2960S will only support dot1q trunking.

Do the command "sh interface switchport" and look at the 5th line under "Administrative Trunking Encapsulation".

rassoul.ghaznavi · ‎01-26-2011

Best way to find out this kind of info is using Cisco feature navigator:

http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp