UFW

cat <<-'EXE'|sudo bash
apt-get update;echo
apt list -a --upgradable
apt-get install -y ufw nmap telnet
EXE

sudo ufw allow http
sudo ufw allow OpenSSH
sudo ufw allow in on lxdbr0
sudo ufw route allow in on lxdbr0
sudo ufw route allow out on lxdbr0

sudo ufw status verbose
sudo systemctl status ufw 
sudo ufw enable

sudo ufw allow 5900/tcp
sudo ufw status verbose

sudo ufw allow http
sudo ufw allow OpenSSH
sudo ufw allow 5900/tcp

ufw status
ufw status verbose
systemctl status ufw

Playground

netstat -a netstat -lpn sudo ufw status apt list --installed netstat -uap|grep nginx	sudo ss -tulwn | grep LISTEN sudo ss -tulpn | grep LISTEN sudo ss -tulpn | grep LISTEN | grep sshd sudo ss -tulpn | grep LISTEN | grep minio sudo ss -tulpn | grep LISTEN | grep resolve	sudo ufw status sudo ufw app list sudo ufw allow 'Nginx HTTP' sudo ss -tulpn | grep LISTEN sudo lsof -i -P -n | grep LISTEN
sudo systemctl status ufw sudo ufw status verbose sudo ufw disable sudo ufw enable sudo ufw status	sudo apt-get install gufw sudo ufw status numbered

References

UFW » Set Up on Ubuntu 22.04
PostgreSQL OpenVPN Minikube Podman Vagrant VSCode NodeJS Docker MAAS MinIO	Academia JavaEE Workspace in Ubuntu Linux Virtual Display for iPad Pro Ubuntu/Raspberry Pi Linux Containers Localtunnel Remmina ActiveMQ MySQL Nginx Qemu