Minimum port configuration required for Trunk mode operation on MES switches:
Trunk configuration
switchport mode trunk
If you need to specify a native VLAN other than 1, the setting will change:
Configuring Trunk and Native VLAN
switchport mode trunk switchport trunk native vlan <NATIVE_VLAN_ID>
where <NATIVE_VLAN_ID> is the VLAN number that will be used for untagged traffic on the port.