Question

I am trying to unblock an IP from which I was doing some tests. I have followed the tutorials on the net:

$ sudo /etc/init.d/denyhosts stop
$ sudo vim /etc/deny.hosts
[remove the last line where I can see my IP to clear]
$ cd /var/lib/denyhosts/
$ sudo vim *
[remove any occurences of my IP to clear]
$ sudo /etc/init.d/denyhosts start

At this moment my IP appears back into /etc/deny.hosts. I tried also:

$ cd /var/lib/denyhosts/
$ echo '123.456.789.122' >> /var/lib/denyhosts/allowed-hosts

I also tried:

$ echo 'my.ip.to.clear' >> /etc/hosts.allow

Unfortunately the hosts.deny always takes precedence, and refuse ssh connection, as can be seen from the log file:

Feb 10 10:06:24 ks123456 sshd[22875]: refused connect from
123.456.789.122 (123.456.789.122)

ref: debian/6.0.4, denyhosts 2.6-10

Answer 1

The instructions to remove an entry for denyhosts can be found here: http://www.cyberciti.biz/faq/linux-unix-delete-remove-ip-address-that-denyhosts-blocked/. In Ubuntu the denyhosts data files are located at /var/lib/denyhosts.

1. Make sure there are not entries that represent the domain name for your IP address in denyhosts.
2. After removing all occurrences of your IP address, and domain name from /etc/deny.hosts (/etc/hosts.deny for Ubuntu) if you are still unable to log in, check the authentication log usually in:
   /var/log/auth.log
   It may give you clues to what your problem is.
3. If you are running linux on both the server and client, you may want to use ssh-copy-id so that you don’t need a password to login to prevent locking yourself out by using the wrong password too many times in the future.

I had problems myself because I had a location saved in Dolphin on KDE to my sever using sftp. Dolphin uses your current username to try logging in which was getting my IP added to the hosts.deny file.