I am facing with a little curious question in terms of COS on untagged port.
My question is that how COS field can be marked in untagged port if i command "switchport port extend cos 1"
generally we can control COS field in accordance with tagged port as known VLAN. but For PC, it works on unttaged port.
There is no COS field in untagged packet. does anybody know about that ?
The following configuration are what I wanna do;
1. VLAN 12 for PC, Data traffic
2. VLAN 200 for IP phone, voice taffic (COS 3 : voice control, COS 5 : voice packet on default behavior)
3. Needs to mark COS 1 for data taffice
Switch --------- IP phone -------- PC
## configuration ##
switchport mode access vlan 12
switchport port extend cos 1
switchport voice vlan 200
mls qos cos trust