Re: [PLUG] Find Open Ports

[JP Vossen <jp@jpsdomain.org>]

BUGFIXES in-line.

JP Vossen wrote:
>  > Date: Mon, 29 Jun 2009 21:07:17 -0400
>  > From: Casey Bralla <MailList@nerdworld.org>
>  >
>  > My employer is very aggressive in closing off ports.  This makes it
>  > hard for me to access my home network from work.  Luckily, port 23 is
>  > open so I can ssh in, and of course, port 80 is left alone.
> 
> As others have pointed out, SSH is 22, not 23.  But it doesn't really 
> matter if you have your SSHd listen on 23 or your firewall foes port 
> address translation (PAT) for 23 --> 22.

As Brian Vagnoni pointer out, doing this may be a violation of company 
policy.  I should have mentioned that, but I got caught up in the 
technical challenge.  :-)

SO.  For educational purposes only...

[snip]
> Fortunately, there is a MUCH better and easier way to do what you want. 
> Since you said you can ssh, just use that.  SSH has this really cool 
> ability to create tunnels.  See my preso on the topic, which has 
> examples for exactly what you want! 
> http://princessleia.com/plug/2008-SSH_port_forwarding_as_VPN.pdf
> 
> My examples are for IMAP, but it's the same thing for your web servers. 
> Let's assume that you have 3 web servers at home, like so:
>     INSIDE            OUTSIDE, from work
>     192.168.1.11:80        << FW PAT 81
>     192.168.1.12:80        << FW PAT 82
>     192.168.1.13:80        << FW PAT 83
> 
> So at work, use PuTTY, SecureCRT (on Win) or OpenSSH (on anything else) 
> and set up your port forwards.  See my PDF, but it would be something 
> like this for OpenSSH, just use the GUI on the other clients:
> 
> ~/.ssh/config
>     Host home
>         HostName foobar.example.com
>         Port 23
>         User root
>         Compression yes
>         ServerAliveInterval = 100
           # BUGFIXES for ending IPA and ports
           #               WORK   -->   Home LAN
           LocalForward localhost:81 192.168.1.11:80
           LocalForward localhost:82 192.168.1.12:80
           LocalForward localhost:83 192.168.1.13:80

Now, on your local machine at *work*, browse to http://localhost:81
to get to 192.168.1.11:80, etc.

Good luck,
JP
----------------------------|:::======|-------------------------------
JP Vossen, CISSP            |:::======|      http://bashcookbook.com/
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