Update of /project/clo/cvsroot/public_html In directory clnet:/project/clo/public_html

Modified Files: faq.shtml Log Message: adding entry about forwarding

--- /project/clo/cvsroot/public_html/faq.shtml 2006/02/09 15:11:55 1.18 +++ /project/clo/cvsroot/public_html/faq.shtml 2006/03/24 20:57:21 1.19 @@ -16,6 +16,7 @@ <a href="#nagging">Nagging</a> <a href="#lgpl">LGPL issues</a> <a href="#sshfingerprint">SSH host fingerprint</a> + <a href="#portsforwarded">Ports forwarded</a> </div>

@@ -109,6 +110,65 @@

<p>RSA: 17:fa:96:e3:30:7d:76:18:d0:59:2d:b5:09:41:fd:db</p>

+ <h1 id="portsforwarded">How can I connect to common-lisp.net through a restrictive firewall via ssh?</h1> + + <p>Some firewall administrators are paranoid enough to disallow + outgoing connections to the ssh port, but they often allow + connections to e.g. the https port. For these cases, we have SSH + running on non-standard ports on shell.common-lisp.net. The + https port is the most common one that is left open, but + sometimes others are open, too. So ssh on shell.common-lisp.net + accepts connections to ports 21 (ftp), 22 (ssh), 23 (telnet), 80 + (www) and 443 (https). + + <p>To find out which ports your firewall lets through, Try to + connect to the ports in order: + +<pre> +telnet shell.common-lisp.net 21 +telnet shell.common-lisp.net 22 +telnet shell.common-lisp.net 23 +telnet shell.common-lisp.net 80 +telnet shell.common-lisp.net 443 +</pre> + + <p>If a port is blocked by the firewall, you'll see something like this: + +<pre> +$ telnet shell.common-lisp.net 443 +Trying 86.59.21.101... +telnet: Unable to connect to remote host: Connection refused +</pre> + + <p>The error message may differ, depending on the firewall's + configuration. + + <p>If you can connect to a port, you'll see something similar to this: + +<pre> +$ telnet shell.common-lisp.net 443 +Trying 86.59.21.101... +Connected to shell.common-lisp.net. +Escape character is '^]'. +SSH-2.0-OpenSSH_3.8.1p1 Debian-8.sarge.4 +</pre> + + <p>If you found a port number that works for you, put the + following segment in the ~/.ssh/config file and substitute the + port that you found: + +<pre> +Host common-lisp.net + Port 443 # substitute the port number you found for 443. + HostName shell.common-lisp.net +</pre> + + <p>If none of the ports on shell.common-lisp.net work for you, + but you can connect to https web sites, you may be running + behind a transparent https proxy. In that case, software like + corkscrew (http://www.agroman.net/corkscrew/) may help you + connect to common-lisp.net. + <a class="topOfPage" href="#top" title="Go to top of page">top</a><br/>

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