I have no problem configuring a trunk link between a 3550 and 2950 switches, and propagating VTP information. However, when I attempt to configure a trunk link between a 3550 and a older 3500XL or 2900XL, I cannot bring the link up. I have checked the encapsulations, and set switchport mode trunk, and desireable, etc. Everything appeared to match, and should have worked. Has anyone else seen this issue? I am I missing something simple?
