We have a trunk link which we use to connect two sites. We have numerous non routed vlans which are running across the trunk. I need to create a qos policy which will give the traffic from one particular vlan priority over everything else. I'm not sure what method I should be using to classify the traffic. Should I use mac-addresses rather than ip addresses as the traffic will be switched or is there a way to classify a particular vlan. Any help greatly appreciated.