auth.log showing attempted access

Brad Johnson brad at
Wed Aug 15 06:30:16 UTC 2007

On Tue, 2007-08-14 at 20:46 -0400, Yuelin Li wrote:
> I see many entries like this in /var/log/auth.log
> sshd[15144]: Failed password for invalid user josh from::ffff: port 2092 ssh2
> How can I trace this computer's location?  More importantly, how can I
> report this person to his/her ISP?  "host" showed that
> this DNS entry can not be reversed.  Traceroute stops at
> (  I have added iptables
> rules (see to try
> to tighten SSH access.  I feel I should do something about it because
> I get a few hundred entries a day coming from the same IP address.
> Yuelin.

The Denyhosts package works wonderfully. It can ban users by adding an
entry to your /etc/hosts.deny file based on the auth.log and can do it
for just sshd, the entire system or any combination of services on your
machine. Additionally, it can treat attempts for root, a valid user and
invalid users differently which is sometimes desirable. Lastly, you can
setup expiry so bans are removed after a period of time. It's even smart
enough to know if a host has been added, then expired and re-added and
can permanently ban as you desire.

Brad Johnson
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