Server Setup - Pre-requisites

Disable hyperthreading on the BIOS/UEFI of your host system. Hyperthreaading is also known as Simultaneous Multi Threading (SMT) on AMD systems. Disabling this is very important for optimal performance of the XDP cpumap filtering and, in turn, throughput and latency.

Boot, pressing the appropriate key to enter the BIOS settings
For AMD systems, you will have to navigate the settings to find the "SMT Control" setting. Usually it is under something like Advanced -> AMD CBS -> CPU Common Options -> Thread Enablement -> SMT Control Once you find it, switch to "Disabled" or "Off"
For Intel systems, you will also have to navigate the settings to find the "hyperthrading" toggle option. On HP servers it's under System Configuration > BIOS/Platform Configuration (RBSU) > Processor Options > Intel (R) Hyperthreading Options.
Save changes and reboot

Install Ubuntu Server 22.04

Install Ubuntu Server 22.04

Set up Bridge

Choose Bridge Type

There are two options for the bridge to pass data through your two interfaces:

Option A: Regular Linux Bridge
Option B: Bifrost XDP-Accelerated Bridge

The regular Linux bridge is recommended for Nvidia/Mellanox NICs such as the ConnectX-5 series (which have superior bridge performance), and VM setups using virtualized NICs. The Bifrost Bridge is recommended for Intel NICs with XDP support, such as the X520 and X710.

To use the Bifrost bridge, be sure to enable Bifrost/XDP in lqos.conf in the Configuration section.

Below are the instructions to configure Netplan, whether using the Linux Bridge or Bifrost XDP bridge:

Option A: Netplan config for a regular Linux bridge

Ubuntu Server uses NetPlan, which uses .yaml files in /etc/netplan to determine interface settings. Here, we will add a .yaml specifically for LibreQoS - that way it is not overwritten when changes are made to the default .yaml file.

sudo nano /etc/netplan/libreqos.yaml

Assuming your interfaces are ens19 and ens20, here is what your file would look like:

network:
    ethernets:
        ens19:
            dhcp4: no
            dhcp6: no
        ens20:
            dhcp4: no
            dhcp6: no
    bridges:
        br0:
            interfaces:
            - ens19
            - ens20
    version: 2

Please be sure to replace ens19 and ens20 in the example above with the correct shaping interfaces. The order of the interfaces does not matter for this section.

By setting dhcp4: no and dhcp6: no, the interfaces will be brought up as part of the normal boot cycle, despite not having IP addresses assigned.

Then run

sudo chmod 600 /etc/netplan/libreqos.yaml
sudo netplan apply

Option B: Netplan config for the Bifrost XDP bridge

sudo nano /etc/netplan/libreqos.yaml