SMC Networks TigerSwitch SMC6128PL2

4-232
• If a VLAN has been added to the set of allowed VLANs for an
interface, then you cannot add it to the set of forbidden VLANs for
that same interface.
Example
The following example shows how to prevent port 1 from being added to
VLAN 3:
Console(config)#interface ethernet 1/1
Console(config-if)#switchport forbidden vlan add 3
Console(config-if)#