Dave,
I have a server that needs to be setup with a trunk port with VLAN 12,14,15,20. It also needs an untagged VLAN 10
Answer: Below is the config to achieve your query:
SwitchA#conf t
SwitchA(config)# interface G1/0
SwitchA(Config-if)#Switch trunk encap dot1q
SwitchAConfig-if)#Switch trunk allowed vlan 12-20 >>These vlans will be tagged.
SwitchA(config-if)#switchport trunk native vlan 10 >>> This cmd will untagged the vlan 10 going out of this trunk port. Make sure the other end also mark the vlan 10 as native to avoid vlan leaking.
SwitchAConfig-if)#Switchport mode dynamic des
Same config to be on the SwitchB port connecting to Switch A.
2- No you need not have to put the vlan 10 in the allowed vlan on the trunk port as you are already defining it as native vlan.( I have tested this and it works without allowing the vlan on the trunk and by just configuring the native vlan..) 100% guaranteed.
HTH
Regards
Inayath
*Plz rate if this info is helpfull.