VF Loopback Pacing

On Linux and Windows Server, the Intel Ethernet 800 Series supports adjusting the loopback rate for a designated port, which allows you to prioritize that port for maximum bandwidth and achieve higher speeds.

On Linux, use the devlink command and the loopback parameter to change this setting.
On Windows Server, use Ethernet Cmdlets for Intel® Ethernet or Intel® PROSet to change the Loopback setting.

Note:

This feature is only supported on Windows Server 2019 and newer versions.

After changing the loopback setting, the driver will reconfigure all underlying VFs to align to the desired port settings and add more bandwidth to VF-to-VF traffic. Setting this parameter to prioritized enables higher hairpin-bandwidth on related PFs.

Note:

This configuration applies only for 8x10G and 4x25G adapter cards.
Typically you would set some ports to prioritized loopback and then disable loopback on other ports, to allow the driver to utilize spare bandwidth for VF-to-VF traffic.
Intel recommends using the prioritized loopback setting on a port with minimal network traffic.
You should first configure loopback on the PF and then configure any other settings, such as VFs/VMs or assigning MAC addresses.

To change this setting with Ethernet cmdlets or Intel PROSet:

This setting is found in the Adapter Settings panel in Intel PROSet ACU.

To change this setting with Ethernet cmdlets, use the Set-IntelEthernetSetting cmdlet. For example:

Set-IntelEthernetSetting -Name "<adapter_name>" -DisplayName "Loopback" -DisplayValue "Prioritized"

To change this setting in Intel® PROSet for Windows PowerShell* software, use the Set-IntelNetAdapterSetting cmdlet. For example:

Set-IntelNetAdapterSetting -Name "<adapter_name>" -DisplayName "Loopback" -DisplayValue "Prioritized"

Possible values for this setting are:

Enabled
Disabled
Prioritized

Virtualization Support

UEFI Network Device Drivers Virtualization Support