Limit a computer's bandwidth to the internet, so the rest of your household don't get starved.
Connect to a VLAN with your Ubuntu 18.04 or 20.04 computer.
A cheatsheet for Ethernet networking.
Set a static IP on your ubuntu 18.04 server using netplan.
How to use iperf to benchmark your network.
This tutorial will ensure you have a running default network on your KVM server.