I am currently working on ICND2 and bought a CCNA lab kit consisting of three 2610 routers and two 2950 Switches. They seem to be just what I need except for one problem, the routers didn't seem to support dot1q encapsulation.
I found this link (see below) in another thread that says dot1q is now supported beginning with 12.2(2)T and later IOS. However, I've loaded several of those updates all the way up to the very latest Enterprise Plus and the encapsulation command is non-existent in all of them. I figure that dot1q must be achieved in a manner I am unfamiliar with then. Any help with this would be greatly appreciated.
802.1Q Encapsulation Support on Cisco 2600/3600 Series Routers [Cisco 2600 Series Multiservice Platforms] - Cisco Systems