cisco catalyst swithcs

The catalyst line of switches is very broad; the capabilities vary widely between models and software loads. I don't think the 'standard' (non-'enterprise') versions of the low-end catalyst switches (1900, 2900, 3500) support trunking, but should be upgradable via software upgrade. I have not seen any restrictions per port; if one port on a module supports trunking, all similar ports on the module should. I have seen modules that will support ISL that don't support 802.1q, but most support both. I've never tried to trunk anything less than 100M / Full duplex; I would suspect it will work at 10M (although poor performance would limit the functionality of this), although I would expect full duplex to be a requirement, by the nature of trunking. Is there a specific model you are interested in? I'd recommend researching at cisco.com for specifics of a particular platform.

Hope this helps.

Chris