Kevin, Check out fail2ban at http://sourceforge.net/projects/fail2ban -- it will scan your logs for invalid access attempts and add iptables firewall rules to block the offending IP addresses after a configurable number of attempts. Richard Wilson EDS richard dot wilson at eds dot com -----Original Message----- From: listbounce@xxxxxxxxxxxxxxxxx [mailto:listbounce@xxxxxxxxxxxxxxxxx] On Behalf Of Zembower, Kevin Sent: Wednesday, July 09, 2008 12:56 PM To: secureshell@xxxxxxxxxxxxxxxxx Subject: Deliberately create slow SSH response? This might seem like a strange question to ask, but is there a way to deliberately create a slow response to an SSH request? I'm annoyed at the large number of distributed SSH brute-force attacks on a server I administer, trying to guess the password for 'root' and other accounts. I think that my server is pretty secure; doesn't allow root to log in through SSH, only a restricted number of accounts are allowed SSH access, with I think pretty good passwords. But still, the attempts annoy me. I wouldn't mind if SSH took say 30 seconds to ask me for my password. This would slow the attempts. Is there any way to configure OpenSSH to do this? I searched the archives of this group with 'slow' and 'delay' but didn't come up with anything on this topic. Please point it out to me if I overlooked anything. In addition, I can limit the number of SSH connections to 3-5 and still operate okay. Ultimately, I need this solution for hosts running OpenSSH_3.9p1 under RHEL ES 4 and OpenSSH_4.3p2 under Debian 'etch' 4.0 and Fedora Core 6. Thanks in advance for your advice and suggestions. -Kevin Kevin Zembower Internet Services Group manager Center for Communication Programs Bloomberg School of Public Health Johns Hopkins University 111 Market Place, Suite 310 Baltimore, Maryland 21202 410-659-6139
