Setting up port-channels on a Cisco switch can sometimes be a real PITA due to your interface settings having to match the port-channel settings. I’ve come up with a way to eliminate the config mismatches, which I’ll describe below.
First we clear the configuration on the interfaces that we’re going to add to our port-channel by doing a “default int gi1/1/1”
Then we add our interfaces to the port-channel and only then do we configure our port-channel, like so:
int gi1/1/1
channel-group <x> mode active
!
int gi2/1/1
channel-group <x> mode active
!
int po<x>
switchport mode trunk
switchport trunk allowed vlan 10,50,...
switchport trunk native vlan 999
This forces your interfaces to join the port-channel before any configuration is added to them. It also reduces the mistake of having mismatched configuration on both interfaces, which could cause independent members in your port-channel.