Define VLANs Allowed on Trunk Link

1. First navigate to the interface for the port or port-channel.

config t
int e1/1

Below for a port-channel.

config t
int channel-groupport-channel 1

2. Ensure the port/port-channel is a trunk.

switchport mode trunk

3. To add a VLAN, use the following command to add the VLANs necessary.

switchport trunk allowed vlan add 7,10,20

4. To remove a VLAN, use the following command.

switchport trunk allowed vlan remove 5-10,12