anyone know about: vlan trunking with catalyst 1900 to any other ios device (catalyst 2950)

It will be difficult to find somewhat recent Cisco device supporting ISL. I don't remember out of top of my head, but 6500 series could be the only option left.

Regards, Andrey.

And the 2950/2960 only supports 802.1q trunking, ISL has been dropped out of almost all of Cisco's product line for modern gear.

You could get some Catalyst 2924xl's for cheap, they would do ISL trunking. Although you say you have 200 devices, you have to watch out for Cisco's STP instant limits, which hard limit the number of VLANs you can run through devices. Ie. the 2924XL has a max STP instance of 64, which means you can't break out or even trunk more than 64 VLANs through them.

Otherwise, you'd have to step up to something like a 4500 or 6500 for the central point with whatever Sup engines support what you need. A basic 4500 with Sup IV will get you 1024 STP instances, and support ISL trunking.

I actually just realised that I have two catalyst 6000 series with 2 supervisor modules and one switching module (both are in centralised points that all the catalysts connect to ... all catalysts are connected via wireless back-hauls using a Motorola product called 'canopy').. Is there anyway I could trunk from the catalyst 1900's to the 6000 series, and then trunk the 6000 series to the 2950?? this would make life MUCH easier...

Otherwise, could I trunk directly to the 6000 series, and ill put some servers in-line with the 6000 series for the web-portal...

I have two 6000 series catalysts?

Yes, the 6500 can talk both ISL and 802.1q trunking. You don't have to preserve the trunking type throughout, you can mix them.

Ok. Do you know of or have any guides as to what to do (configuration wise) in this case? Sorry for my ignorance, I'm new to this.

Cheers,

The manuals should still be online on CCO. A few things to know/ remember :

- 1900's have a funny way of handling more than the max # of spanning trees. Preferably do not use VTP and set up manually, allow only the vlans required towards the 1900

- ISL support in the 6xxx and other switches depends on the port ASICs not on the supervisor, check module type

- there once was a nice hardware bug which caused occasional unicast (!) storms when using ISL trunks/channels between 6xxx's and 1900s. I don't remember the details but I had an interesting time finding out at the time ...

apart from that, no reason why it shouldn't work. If you want to trunk via wireless verify it supports max size packets plus dot1q, try ping using largish packet size like 1500

luck, Frans

Sure, there's lots of them here.