By default, a virtual NIC on a guest VM operates in access mode. In this mode, the virtual NIC can send and receive traffic only over its own VLAN, which is the VLAN of the virtual network to which it is connected.

A virtual NIC in trunk mode can send and receive traffic over any number of VLANs in addition to its own VLAN. You can trunk specific VLANs or trunk all VLANs. You can also convert a virtual NIC from the trunk mode to the access mode, in which case the virtual NIC reverts to sending and receiving traffic only over its own VLAN.

Trunked NIC can only be added via acli.

It is not possible to distinguish between Access and Trunked NIC modes in Prism UI.

You can create new NIC for the VM to operate in a required mode or you can change the mode of an existing VM NIC.

For the command list and sequence please rerfer to AHV Administration Guide: Configuring a Virtual NIC to Operate in Access or Trunk Mode