Cygwin sshd problems

February 14, 2008 11:57 AM

Cygwin sshd two-part question.

1. Why does the sshd service sometimes interfere with program installations (making the installer hang)?

2. Why did a machine that used to allow remote ssh logins suddenly start refusing with the message "ssh_exchange_identification: Connection closed by remote host" ?

For the first part, now I try to just kill the service before I install anything so I can prevent the installer from hanging. For the second part, it's conceivable that the remote host has some very old version compared to the local host.

Both hosts are running win2k.

posted by Calibandage to computers & internet (5 comments total)

The cygwin mailing list (also available via Gmane) is the best resource for this kind of question, as long as you follow their problem reporting guidelines.
posted by grouse at 12:20 PM on February 14

Whenever I get SSH problems (I'm using CopSSH) the only thing I can do to fix it is reboot (WinXP).
posted by blue_beetle at 12:36 PM on February 14

no 1 could be any number of windows related issues surrounding file and registry contention.

no 2 sounds like a KEX problem. Often the issue is a mismatch in the list of ciphers, macs, or authentication methods. Take a look at the /etc/ssh_config file on the server, and compare to the client machine. In general, the KEX process is fairly robust, but if one side is insisting on a cipher the other side doesn't have, there's nothing left for it to try next. If nothing is obvious from the config files, try starting the sshd manually on the server, in debug mode, and post any interesting messages that get logged during a connection attempt.
posted by nomisxid at 2:41 PM on February 14

I've been using Cygwin sshd on WinXP Pro for a couple of years now and never noticed it causing installation failures. Also never seen the error message in number 2....have you considered reinstalling the sshd ?
posted by AltReality at 2:44 PM on February 14

Okay, sorry to answer my own post, but #2 turned out to be the version issue. Updates for both machines cleared up the problem, sorry for the waste of space, thanks for your time nomisxid and AltReality. I'll be happy if the update fixes the installation problems, but I've been through several versions with this same issue (but all on win2k, which could very well be the problem).
posted by Calibandage at 3:03 PM on February 14