SSH – Preventing Brute Force Attacks

brute-force-attacksSecurityssh

What tool or technique do you use to prevent brute force attacks against your ssh port. I noticed in my Security logs, that I have millions of attempts to login as various users through ssh.

This is on a FreeBSD box, but I imagine it would be applicable anywhere.

Best Answer

Here's a good post on that subject by Rainer Wichmann.

It explains pros and cons on theses methods to do it :

  • Strong passwords
  • RSA authentication
  • Using 'iptables' to block the attack
  • Using the sshd log to block attacks
  • Using tcp_wrappers to block attacks
  • Port knocking
Related Topic