Just setup GUFW Rules: outgoing ALLOW , incoming ALLOW 22, 25/tcp, 80, 110, LIMIT ssh/tcp. This is a server. I'll probably change port for ssh and close 22 later. When firewall is on, I can ping (from LAN client) to the gateway, an adsl modem router 192.168.1.1 but "cannot find host google.com" when I ping that. With firewall off I can ping it. What am I missing?