Linux login

How to configure the linux login in order to be safer.

Change the port sshd listens to

Uncomment and change the line containing port 22 to port 2996

> vim /etc/ssh/sshd_config
sshd_config> port 2996

This one really helps a lot!

Is there a way to check on ip lists and ban recursive ips failing to login?

The best way that I have found for doing this is this:

> sudo iptables -A INPUT -i eth0 -p tcp --dport 22 -m state --state NEW -m recent --set --name SSH
> sudo iptables -A INPUT -i eth0 -p tcp --dport 22 -m state --state NEW -m recent --update --seconds  60 --hitcount 8 --rttl --name SSH -j DROP

The downside to this is that every time you reboot or restart iptables you have to do this again. The easiest thing to do is put it in a bash script. There is a great article @ TechBlog - How to: Block brute force attacks with iptables.

External References

• TechBlog article;
• Forum post.