Hi Jeff
If you are using the term "trunk" in the Cisco sense i.e. an interface with an untagged VLAN plus multiple tagged VLANs then there is no special configuration required, just add ports to VLANs.
Example; Port 48 is already in VLAN 1 but you want VLAN 10 as untagged and VLAN 20 as tagged.
Hostname#conf t
Hostname(config)#vlan 20
Hostname(config-vlan-20)#tag e 1/1/48
Added tagged port(s) ethe 1/1/48 to port-vlan 20.
Hostname(config-vlan-20)#vlan 1
Hostname(config-vlan-1)#no untag e 1/1/48
Hostname(config-vlan-1)#vlan 10
Hostname(config-vlan-10)#untag e 1/1/48
Added untagged port(s) ethe 1/1/48 to port-vlan 10.
Hostname(config-vlan-10)#
The config. would look like this;
Hostname(config-vlan-10)#sho run
...
!
!
vlan 1 name DEFAULT-VLAN by port
!
vlan 10 by port
untagged ethe 1/1/48
!
vlan 20 by port
tagged ethe 1/1/48
!
!
...
You can get the full set of config guides here;
https://docs.arris.com/bundle?labels=203&labels=209&labels=208&labels=207&labels=206&labels=206&labe...