Black Screen PuTTY and SSH on Slackware 10
 

I have slackware 10 installed and the OpenSSH 3.9p1. When I try and connect to the server through PuTTY on Windows XP sp2 I just get a blank screen. The logon prompt never comes up. When I first installed the server I connected once and then I got the above problem. I thought it was my version of OpenSHH so I upgraded it. I cannot connect to the server outside of my local network on my and a different XP machine. Also, I can connect to the server through another linux box that is outside of the LAN. Any ideas how to get it to connect?

Thanks,
C

are you using a valid user name? when you connect?

you also might wana see if you can try to log on using ssh on a *nix machine (that will tell you for sure where the problem lies,client or server)

Are you sure the server is running, in linux side try:

netstat -an | grep tcp.*22.*LISTEN

And in windows side what is the output for :
telnet <your linux machine IP> 22
in a cmd prompt

Re: Black Screen PuTTY and SSH on Slackware 10
 

Is it just when you try to connect through Putty? Have you tried to connct through another SSH client? Have you tried connecting through a Linux box? Maybe there's something wrong with your version of Putty.
Also, is the IP for the Windows box you're using on your hosts.allow file to allow connection to your Linux box? I had that problem once when I came back to my parent's house for a weekend. I added their IP to my hosts.allow file before I left, but their IP changed while I was here (somone turned off the DSL modem for some reason, and it got a new IP when it was turned back on), and I could no longer connect to my computer. I would get just a blank screen on Putty when that happened.

When I type the netstat command I get this:

tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN

On the XP machine I get a blank screen.

I re-posted my original reply and can connect on trhough a linux machine outside of my network.

I don't have anything in my host.allow file.

How is your ssh server connected to the Internet? Is it directly connected or is there a router? If there is a router, do you have it set up to forward port 22 to the ssh server box?

It is connected through a router and it is already set to foward the port to it.

I would think you have a built-in firewall in XP that block tcp 22 port, it should
display the SSH banner when telnet to linux machine with port tcp 22 at cmd prompt.

OK, after re-reading your posts, I guess I'm confused about what you can and cannot do. Let me rephrase your posts and please tell me where I'm wrong.

- You cannot connect to the ssh server from XP either from within your LAN or from outside
- You can connect to the ssh server from Linux both from within your LAN and from outside


If this is the case, then I'd bet that the XP firewall is the problem.

Just one correction to what you stated above:
-I don't know if I can connect to the server through a Linux box
within my LAN b/c I don't have another linux box.

Second, my XP firewall is turned off on my laptop.

Third, I get a blank screen on PuTTY and never get a loging prompt.

Fourth, when I use puTTY from the XP machine to connect to another Linux server on port 22 outside my LAN I get a login prompt

hmm this is quite odd, I use PuTTy daily at work from a XP machine to a server (outside on the internet)... I never had an issue with it. But one difference that I see is that I used the sshd that came with the distro,

That seems more clear now, you did never success to connect with SSH to your linux box in your
lan ?
Have you a firewall in the linux box, could you ping the linux box from cmd XP prompt ?

If you've never been able to make an ssh connection to your linux box in any form, I second the notion that your linux firewall may be the problem. Please post your firewall script or the output of iptables -L

I did use the sshd with the distrubution and it didn't work either that is why I upgraded

I can ping the server from the xp machine

The iptables gives me this:

Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FOWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination