I'm trying to connect two identical Catalyst 3550 via GBIC. When I connect the two switches port g0/1 on both switches becomes up, but they can't talk to each other. They both have the same IOS, Version 12.1(12c)EA1.
Usually when I GSTACK two 3750, the second switch becomes part of stack automatically and I can do a show inter and see inter g1/0/48 to g2/0/48, but this is not the case with these 3550.
Is there any commands that I need to do on these 3550 to join them together in one stack?