SSH forward from a Windows machine to a Linux machine isn't working

nickj6282 · 08-12-2006, 12:48 AM

Hello all,

I have a SuSE 10.1 machine with a number of private IP addresses which is connected to the internet via a Windows Server 2003 machine. Basically, the Windows box has an external interface and an internal interface and acts as the NAT router for the LAN. I set up a port forward from the external interface on the Windows box to the Linux machine, but I can't connect to it.

When I try to connect from OSX, it just times out. If I run dmesg | tail this is what I get:

Code:

susebox:/etc/ssh # dmesg | tail
martian source 192.168.200.20 from <my home IP address>, on dev eth0
ll header: 00:60:08:cf:14:89:00:02:55:fc:29:ed:08:00
martian source 192.168.200.20 from <my home IP address>, on dev eth0
ll header: 00:60:08:cf:14:89:00:02:55:fc:29:ed:08:00
martian source 192.168.200.20 from <my home IP address>, on dev eth0
ll header: 00:60:08:cf:14:89:00:02:55:fc:29:ed:08:00
martian source 192.168.200.20 from <my home IP address>, on dev eth0
ll header: 00:60:08:cf:14:89:00:02:55:fc:29:ed:08:00
martian source 192.168.200.20 from <my home IP address>, on dev eth0
ll header: 00:60:08:cf:14:89:00:02:55:fc:29:ed:08:00

So as you can see, I'm getting through to the box, but it's silently ignoring me. If I check /var/log/messages, this is what I see:

Code:

susebox:/etc/ssh # tail /var/log/messages
Aug 12 00:34:31 susebox kernel: martian source 192.168.200.20 from <my home IP address>, on dev eth0
Aug 12 00:34:31 susebox kernel: ll header: 00:60:08:cf:14:89:00:02:55:fc:29:ed:08:00
Aug 12 00:34:43 susebox kernel: martian source 192.168.200.20 from <my home IP address>, on dev eth0
Aug 12 00:34:43 susebox kernel: ll header: 00:60:08:cf:14:89:00:02:55:fc:29:ed:08:00
Aug 12 00:35:07 susebox kernel: martian source 192.168.200.20 from <my home IP address>, on dev eth0
Aug 12 00:35:07 susebox kernel: ll header: 00:60:08:cf:14:89:00:02:55:fc:29:ed:08:00
Aug 12 00:37:40 susebox smbd[23009]: [2006/08/12 00:37:40, 0] printing/print_cups.c:cups_cache_reload(85)
Aug 12 00:37:40 susebox smbd[23009]:   Unable to connect to CUPS server localhost - Connection refused
Aug 12 00:37:40 susebox smbd[23009]: [2006/08/12 00:37:40, 0] printing/print_cups.c:cups_cache_reload(85)
Aug 12 00:37:40 susebox smbd[23009]:   Unable to connect to CUPS server localhost - Connection refused

I read somewhere else that this problem might be caused by multiple ethernet cards in one machine, but this machine has only eth0. Any suggestions anyone?

Thanks,
-Nick

Brian1 · 08-12-2006, 09:59 PM

Just to make sure of some things are correctly setup.

Windows is doing Nat
Windows port forward is setup
Firewall on windows has the external IP port open

Linux box IP port is opened through firewall

Are you using keys or passwords?
Have you connected from the windows machine to the linux box?

Brian1

nickj6282 · 08-13-2006, 01:47 AM

Yes.
Yes.
Yes.

The port that SSH listens on is open on the SuSE firewall. That same port is open on the firewall of the Windows box and is forwarded to the Linux box. The presence of my home IP address in /var/log/messages confirms that I am indeed getting through. I'm using passwords, and yes, I can putty from the Windows machine to the Linux machine. I just can't directly ssh from home (250 miles away) to the linux machine via the port forward on the Windows box. It times out. Must be some configuration that's telling it my home IP address is bad, but I can't figure out where to make the change.

Thanks,
-Nick

Brian1 · 08-13-2006, 02:47 PM

Not sure about the configuration.
Post contents of /etc/ssh/sshd_config

One thing I would try as a try if the system can be down. Get hold of one of those store bought routers and configure it to take the place of the windows box. Then setup portforwarding and see if you can get in that way. If so then an issue on the Windows box. If still no go then I would lean towards the linux box as the issue. Then have a friend or someone at home try to connect from the outside.

Check out this post on sshd setup. Might have missed something. http://www.suso.org/docs/shell/ssh.sdf

Brian1