Firewall allow libvirt VM NAT Network (converted to ufw commands)

ufw-allow-vm-nat.sh

#!/bin/bash

# Firewall allow libvirt VM NAT Networking (converted to ufw commands)
# Ref: https://wiki.archlinux.org/title/Libvirt#Using_nftables

# The old solution is to set `firewall_backend=iptables` in `/etc/libvirt/network.conf`
# instead of setting firewall rules in nftables, ufw, etc.
# However, this uses the legacy iptables backend and should be considered deprecated.

sudo ufw allow in on virbr0 to any port 53 proto udp comment 'allow VM DNS requests to host'
sudo ufw allow in on virbr0 to any port 67 proto udp comment 'allow VM DHCP requests to host'
sudo ufw route allow in on virbr0
sudo ufw route allow out on virbr0

# You must reboot the system after adding these rules. Based on my testing, only restarting services is not sufficient.