trunking question

[zoomzale1]

when typing the command, "switchport trunk allowed vlan add [number]", will the existing trunk link stay up and functional?

What if it's a port-channel? will the port-channel stay up if the allowed vlans do not exactly match on each side of the channel?

Thanks!!

[glen.grant]

Yes the trunk will stay active , has no effect on the active trunk if you are just adding a vlan to the trunk . I think it will stay up on the etherchannel as long as you do them within a short period of time of each other , if you do one side and wait 5 minutes it may tear down the channel.