Here's what I have already figured out by reading Cisco's literature...
-If I create a VLAN on a few ports, using the following commands: switchport mode access switchport access vlan 42
-The switch allows untagged packets to ingress the port. And, any packets ingressing the port are associated with VLAN 42.
So, my question is how do I configure a port to tag packets as they egress the port AND ... require ingress packets to already be tagged with VLAN 42.
Could it be such a simple solution? Anyway, any help would be appreciated.