It is very Tricky with Extreme (XOS or Extremeware) stuff:
- There is no "native" command in Extreme, You HAVE to define a new 'control' vlan, tagged 100, for example
- Now on CISCO side, you HAVE to define Native vlan 100
- You only need 1 uplink to pass all the vlans you want.
Saludos from Mexico!,
Ivan