ufw is the default firewall available with Ubuntu. It is an easy to use interface to linux iptables. By default ufw is disabled on Ubuntu. To enable, run
ufw enable
Disable firewall
ufw disable
To see status of firewall
ufw status Example root@server:~# ufw status Status: active To Action From -- ------ ---- Nginx HTTP ALLOW Anywhere 80 ALLOW Anywhere 21/tcp ALLOW Anywhere 20/tcp ALLOW Anywhere 8000 ALLOW Anywhere 443/tcp ALLOW Anywhere 6000:6010/tcp ALLOW Anywhere 6000:6010/udp ALLOW Anywhere 5900:5920/tcp ALLOW Anywhere 5900:5920/udp ALLOW Anywhere 5901 ALLOW Anywhere 5900 ALLOW Anywhere 6000 ALLOW Anywhere 6001 ALLOW Anywhere 8181/tcp ALLOW Anywhere 8181 ALLOW Anywhere Anywhere ALLOW 61.206.127.63 Anywhere ALLOW 133.232.67.215 Anywhere ALLOW 198.50.234.187 22/tcp ALLOW 198.50.234.187 22/tcp ALLOW 133.232.67.215 Nginx HTTP (v6) ALLOW Anywhere (v6) 80 (v6) ALLOW Anywhere (v6) 21/tcp (v6) ALLOW Anywhere (v6) 20/tcp (v6) ALLOW Anywhere (v6) 8000 (v6) ALLOW Anywhere (v6) 443/tcp (v6) ALLOW Anywhere (v6) 6000:6010/tcp (v6) ALLOW Anywhere (v6) 6000:6010/udp (v6) ALLOW Anywhere (v6) 5900:5920/tcp (v6) ALLOW Anywhere (v6) 5900:5920/udp (v6) ALLOW Anywhere (v6) 5901 (v6) ALLOW Anywhere (v6) 5900 (v6) ALLOW Anywhere (v6) 6000 (v6) ALLOW Anywhere (v6) 6001 (v6) ALLOW Anywhere (v6) 8181/tcp (v6) ALLOW Anywhere (v6) 8181 (v6) ALLOW Anywhere (v6) root@server:~#
Allow a Port
To allow both tcp/udp on port 80, run
ufw allow 80
To allow TCP connection on port 80, run
ufw allow 80/tcp
Deny a Port
To deny all connection to port 80
ufw deny 80
To deny incoming tcp packets on port 80
ufw deny 80/tcp
Remove allowed port
If you allowed a port and want to remove it, you can run
ufw delete allow 80
Allow SSH access from Only specified IP
ufw allow proto tcp from YOUR_IP_HERE to any port 22 ufw delete allow 22
