# .................. ufw question
$ sudo ufw reset
$ sudo ufw status
Status: inactive
$ sudo ufw enable
Firewall is active and enabled on system startup
$ sudo ufw deny ssh
Rule added
Rule added (v6)
$ sudo ufw status
Status: active
To Action From
-- ------ ----
22 DENY Anywhere
22 (v6) DENY Anywhere (v6)
$ nmap localhost
Starting Nmap 7.01 ( https://nmap.org ) at 2017-01-01 00:45 MST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000046s latency).
Not shown: 994 closed ports
PORT STATE SERVICE
22/tcp open ssh
111/tcp open rpcbind
139/tcp open netbios-ssn
445/tcp open microsoft-ds
$ nc -zv localhost 22
Connection to localhost 22 port [tcp/ssh] succeeded!