Questions about changing allowed vlans on port channel in a VPC

[andrewjinks]

We have the following identical configuration on 2 Nexus 9K switches in a VPC configuration (both using port Ethernet1/10, both using PO10, and both in VPC10):

interface Ethernet1/10
description uplink to vSphere vDS 1
switchport
switchport mode trunk
switchport trunk allowed vlan 100,300,400,500
channel-group 10 mode active
no shutdown

interface port-channel10
description trunk-to-vDS
switchport
switchport mode trunk
switchport trunk allowed vlan 100,300,400,500
vpc 10

There are two Nexus 9K switches in this VPC configuration, and two cables - 1 per switchport, per switch - uplinking to a distributed switch in a vSphere system using a LAG/LACP.  Questions:

1) Is it necessary to have the regular switch port configured as a trunk, as well as the port-channel it's in configured as a trunk?  Or, just configure the port-channel alone as a trunk?
2) If both, and if I want an additional Vlan allowed over this trunk/VPC (200), do I need to update the switch interface config, the port-channel interface config, or both?
3) Does updating the "switchport trunk allowed vlan" command cause any downtime if you have to update one or both?
4) Is there a command structure for updating the "switchport trunk allowed vlan" command on multiple interfaces at the same time?

[Joseph W. Doherty · Accepted solution]

Logically, the port-channel interface should be the only interface you need to configure, except for adding/removing port as a port-channel member  However, over the years you may have had to configure individual member ports with some commands, but need for that has also decreased over the years.  I.e. try configuration changes on port-channel interface first.

Anytime you make a configuration change, assuming it's a "good" change, there's still some chance of network interruption, possible, some of which is so brief, it goes unnoticed.  I.e. it's good practice to make all configuration changes during scheduled maintenance.

[andrewjinks]

I added the vlan to the port-channel and it automatically added the vlan to the interface config as well.  The correct format was:

config t
interface port-channel 1-10
switchport trunk allowed vlan 100,200,300,400,500

Thanks!