I'm running a SSH server at home to allow me to connect to my computers when I'm away from home. This server is attacked regularly and I don't like it!
Even though I use keys based authentication and no one has successfully compromised my server I'd like to see what can be done about this.
I'm thinking about only allowing IP's from my country (the Netherlands) to connect. Using this site I was able to download a list with all the netblocks in NL. Surprise! There are so many small netblocks in there setting them all up is out of the question.
When I would allow 24.x.x.x, 62.x.x.x-93.x.x.x and 129.x.x.x-217.x.x.x I would allow most of the internet again.
An interesting blog post on NEOHAPSIS.
I'll let you know when I know more.