The Cisco IOS XRv Router maps the router Ethernet interfaces to
the logical vNIC name assigned by the VM, which in turn is mapped
to a MAC address on the VM host.
To add or delete a vNIC from the VM, you must first power down the VM. If you delete any vNICs, the router must be rebooted. For more information about adding and deleting vNICs, see the VMware Documentation.
We recommend that you exercise caution before removing any existing vNICs
on the Cisco IOS XRv Router VM. If you remove a vNIC without first
updating the Cisco IOS XRv Router network interface configuration, you
risk a configuration mismatch when the router reboots. When the
router reboots and a vNIC is removed, the remaining logical
vNIC names may get reassigned to different MAC addresses. As a
result, the Ethernet network interfaces on the Cisco IOS XRv Router may get reassigned to different vNICs.