As part of vSphere 7.0, ESXi now ships with a USB CDCE (Communication Device Class Ethernet) driver which can benefit customers with SB network adapters that support the CDCE specification as shared in this blog post HERE. This can especially be useful for those running a VMware Homelab where the onboard network adapter may not be supported and using a CDCE USB network adapter would allow you to install ESXi.
When a CDCE-supported USB network adapter is connected to an ESXi host, it will automatically be claimed by the CDCE driver as shown in the screenshot below.
If you are planning to use the USB network adapter for VMkernel traffic, then there is no workflow change like any other physical network adapter. However, if you intend to passthrough the USB network adapter to a VM, then you may find that it is not working as expected.
The reason for this is that ESXi has already claimed the USB device, assuming you wish to use it for VMkernel traffic. To change the behavior for a particular CDCE-supported USB network adapter, we just need to apply a USB Quirk which tells ESXi to ignore this adapter.
Step 1 - Run the following ESXCLI command to retrieve the desired USB network adapter and make a note of both the ProductID and VendorID (0xAAAA and 0xBBBB). In this example, the ProductID is 0x0bda and VendorID is 0x8153.
esxcli hardware usb passthrough device list
Step 2 - Next, we configure the USB Quirk and replace our ProductID and Vendor ID into the following string: 0xAAAA:0xBBB:0:0xffff:UQ_NET_IGNORE and then run this ESXCLI command:
esxcli system settings advanced set -o /USB/quirks -s 0x0bda:0x8153:0:0xffff:UQ_NET_IGNORE
Step 3 - Finally, we just need to reboot for the change to go into effect and after that, our CDCE USB network adapter can now be passthrough to a VM