Converting from ISL to 802.1q

[jhowell]

I have a switched network with a 6509 and a bunch of 2924's and 3548's that has been using ISL for its trunking protocol. Now I've purchased some 2950's and have discovered that they don't support ISL and I have to convert to 802.1q. How painful is this going to be? Any gotchas that I need to be aware of?

[Prashanth Krishnappa]

It should be pretty straightforward change. But make sure the native VLAN on both switches match for a dot1q trunk. Also the following page should be useful

http://www.cisco.com/warp/public/473/#Trunking

[jhowell]

Thanks. I didn't think it would be too difficult, but you never know. Is the lack of ISL support a trend? I've been looking for some sort of statement on the website that would indicate whether Cisco was going to continue to support ISL in future products but haven't yet found anything.

[Prashanth Krishnappa]

We will continue supporting ISL, but lot of customers prefer dot1q since it's a IEEE standard