Imagine this topology:
[PC] ------- [VOIP Phone] ------- [eth0/0 on a Switch]
And this configuration on the switch:
vlan 22 name DATA vlan 33 name VOICE
There are two ways to have both the PC's traffic and the VOIP phone's traffic "arrive" on eth0/0 in distinct VLANs. 1. Use a Trunk port, 2. Use the Auxillary VLAN feature".
int eth0/0 switchport mode trunk switchport trunk native vlan 22 switchport trunk allowed vlan 22,33
int eth0/0 switchport mode access switchport access vlan 22 switchport voice vlan 33
The net effect of either of these is the same untagged traffic from the PC arrives and is accepted into VLAN 22 (the data VLAN), and tagged traffic from the VOIP phone arrives and is accepted into VLAN 33.
What are the benefits of using Option 1 or Option 2? What reasons exist that make either of these better than the other?