[OT] How to Diagnose Problem Inboud Connect Through Router?

[Rafael Carneiro]

You can use telnet to find out if you have connectivity to an open TCP port.

So *telnet <your-public-ip> 22* should just open with a banner like
"SSH-2.0-OpenSSH_5.3p1 Debian-3ubuntu3".

It should just work from any machine within your own network (granted that
you properly forwarded that port and disabled any firewalls). If that works,
then you should test it from somewhere else, which should also work but then
you depend on port TCP/22 being allowed (outbound) wherever you decide to
run that from.

If you're considering leaving SSH open to the world, make sure you have a
strong password and not obvious username as well as iptables/fail2ban or
something of that nature to protect yourself. There are a lot of wannabe
hackers out there scanning public IPs.

Rafael


On Thu, May 20, 2010 at 8:32 AM, Stephen <stephen-d-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org> wrote:

> I have set up OpenSSH on my Linux server and Putty as a client on my
> Windows laptop.
>
> They connect just fine at home.
>
> I set the router's firewall to forward port 22 to the Linux server.
>
> I can ping the router just fine. But I get unable to connect errors when
> trying to connect using SSH.
>
> How can I diagnose this?
>
> I am thinking that I connect the laptop to the WAN port on the router, hard
> code IP's for the wan port and the laptop and go from there. Am I on the
> right track?
>
> Thanks
> Stephen
> --
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-- 
Rafael Carneiro
http://ca.linkedin.com/in/rcarneiro
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