When deploying a Virtual Machine in UPT mode you may observe the following issues:

• Virtual Machine configured with a virtual NIC on a DPU-backed distributed switch, and UPT mode enabled continuously displays the following warning:  "The UPT(Unified Pass Through) is not activated on network adapter"
• Checking the port status confirms the port is in PT_None instead of PT_UPT mode.

This error is caused by the Virtual Machine guest operating system not running a VMXNET 3 driver capable of supporting UPTv2. When this occurs, the virtual NIC is functional but not operating in UPT mode. 

To resolve the issue, please follow the below mentioned process:

Windows operating systems

Installing the latest VMware Tools included with vSphere 8 provides the required VMXNET3 driver. Refer to the article Installing and upgrading VMware Tools in vSphere (2004754).

Linux operating systems

The VMXNET3 driver is part of the Linux kernel modules. In early 2022 VMware upstreamed the new VMXNET3 driver with UPT support to the official Linux kernel 6 sources. As distributions update to the new kernel, they automatically pick up the new VMXNET3 driver. 

Since each distribution independently manages their adoption timeline, the availability of the required VMXNET3 driver depends on the distribution owner.   

Availability: As of December 2022, VMware has confirmed the new VMXNET3 driver present in the following Linux distributions. The list of Linux distributions with native UPT support will grow as the adoption of Kernel 6 increases.

• Centos Stream 9
• Debian 11.5 (requires upgrading to optional kernel 6)
• RHEL 8.7
• RHEL 9.1
• SLES 15 SP4
• Ubuntu 20.04 (requires upgrading to optional kernel 6)
• Ubuntu 22.04 (requires upgrading to optional kernel 6)
• VMware Photon 3
• VMware Photon 4

Note:

• The process to upgrade or switch to kernel 6 varies by distribution. To obtain the procedure for your distribution and support status, please consult the distribution maintainer.
• It is possible to independently compile a kernel or driver using the sources available from the Linux Kernel Archives. While this is an option for testing, this is not a recommended approach for production workloads. Please consult with the distribution maintainer on the support impact of using a custom kernel.