I've been using passwordless ssh on my home network for ages. Suddenly, one particular system (ubuntu 7.10) is suddenly requiring a password for incoming connections. From that machine, you can ssh w/o password to other machines on the network. I'm stymied. Where do I start looking to debug this problem? I did regen the system's ssh_host keys w/o effect.

best place to start is always the /var/log/ usually (in most distros) any errors with ssh will be logged to /var/log/messages. So tail -f /var/log/messages and try logging into that box again and see what it says.

Also it should be helpful if u check the /var/log/secure log files. Try regenerating the public keys and copying them to the authorized_keys file. [Modified by: Peter on June 18, 2008 07:20 PM]

You can also use the ssh command itself to help with a bit of debugging. You can use the flag -v (and continue to increase the number of v's -vvvv) to get troubleshooting and debug help. ...corey

Most likely, your private key is weak as a result of the [url=http://wiki.debian.org/SSLkeys]Ubuntu/debian OpenSSL vulnerability[/url]. Run ssh-vulnkey after logging in to check whether this is the case. If your key is affected, you'll have to regenerate it. [Modified by: phihag on June 29, 2008 04:09 PM]

solved! [quote] Jun 29 12:30:37 kmac sshd[4844]: Authentication refused: bad ownership or modes for directory /root [/quote] Don't ask me how, but the ownership of /root had been changed. It's alway something dumb, isn't it? :( [Modified by: jeffelkins on June 29, 2008 06:58 PM]