Hi A small question please, on Cisco ME3400/3800 With this config: interface GigabitEthernet0/15 switchport trunk allowed vlan none switchport mode trunk speed 100 duplex full no cdp enable service instance 11 ethernet encapsulation dot1q 1-4094 bridge-domain 909 ! The cisco encapsule the Spaning tree and other L2 Protocole into the vlan 909 ? thanks Olivier