Hi. I got a LAN with IPs ranging from 192.168.1.65 (router), 192.168.1.66 (server) to 192.168.1.100 (PCs). the server is an ubuntu 6.10 machine. all the rest of the machine are running windows xp and ubuntu 6.10. All of the machines can connect to the server through ssh by making use either open-ssh or putty. the problem arises with one PC (192.168.1.66) which is a dual boot win xp and ubuntu 6.10. in win xp i can access the server by making use of putty. while in ubuntu i cannot connect to the server. any ideas why? i can ping the server but i cannot see it.

The things that come immediately to mind are a firewall issue at either end of the wire, tcpwrappers on the server or possibly a configuration issue with sshd. (On the configuration issue, I thought I had read that you could used sshd_config to limit which hosts can connect, but glancing through the man page, I don't see it.)

If you don't see any obvious problems here, I would suggest using a packet sniffer like tcpdump or wireshark to see what is actually going on at a packet level.

both machines do not have a firewall in between. there is no setup for limiting an IP address. the thing is that this machine has the same IP when in winxp and it works perfect.

I would use a packet sniffer when you try to ssh and see what packets are actually leaving and entering both machines. Then at least you would have something concrete to work with.

ok i will give it a try and then see what it will bring me.

the following is what happens when i ssh from 192.168.1.66 to 192.168.1.65

aris@aris-desktop:~$ ssh binary@192.168.1.65@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
ec:62:60:ee:..............................03.
Please contact your system administrator.
Add correct host key in /home/aris/.ssh/known_hosts to get rid of this message.
Offending key in /home/aris/.ssh/known_hosts:1
RSA host key for 192.168.1.65 has changed and you have requested strict checking.
Host key verification failed.
aris@aris-desktop:~$

I'm a bit confused now. Is post #6 about your original problem? If so, you are connecting OK, but the RSA host key is different than your local host expects. If this is all on a LAN that you can trust (in other words, if you know that nobody is trying to do anything nasty), you can just delete the old/wrong key in /home/aris/.ssh/known_hosts (I am not sure what the ":1" is; I don't think it is part of the file name) and let ssh get the correct key the next time. If you don't have the ability to trust the network then you need to find a trustworthy way to get the correct key from 192.168.1.65 installed on 192.168.1.66.

If you trust the network and wish to simply remove the offending key, you can edit known_hosts with an editor and remove the line (they are long lines that will probably wrap around several times) for 192.168.1.65. You could also just delete the file, but if you have more than that one key in there you would then have to reestablish all the other keys. If there is any reason not to trust the network, be careful.