<p>As root, run:</p> <pre><code>netstat -tunap </code></pre> <p>you should receive something that looks like this:</p> <p>Active Internet connections (servers and established)</p> <p>Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name</p> <p>tcp 0 0 0.0.0.0:37 0.0.0.0:* LISTEN 3425/inetd</p> <p>tcp 0 0 0.0.0.0:6000 0.0.0.0:* LISTEN 3640/X</p> <p>tcp 0 0 0.0.0.0:113 0.0.0.0:* LISTEN 3425/inetd</p> <p>tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 7586/sshd</p> <p>0.0.0.0:* indicates port 22 is listening on all addresses.</p> <p>To search only for sshd, pipe netstat with grep:</p> <pre><code>netstat -tunap | grep sshd </code></pre>