http://www.kevinschick.com/2016/06/network-attacks-ufw-is-working-but-more.html
http://www.kevinschick.com/2016/06/tenacious-attackers-network-exploiters.html
I could not resolve the server by IP or name at all yesterday. I quickly found that the systems engineer at the data center didn't verify the asset tags on the servers involved, and wiped out everything of mine by mistake.
It was an experimental server, so I did not panic or freak out. The new set up will be running with ESXi and I will be able re-install and manipulate it via vsphere. I also took this as an advantage to move away from Debian and jump into CentOS. I used Redhat many years ago, pre-Fedora to be more precise, so the transition back to rpm goodness should not present any real issues or giant hurdles.
I look forward to the change.
I will concentrate on hardening the server, and experimenting with attackers. A honeypot is tempting. The first paragraph of the Wikipedia article describes a honeypot very well. I think analysing hacker activity and how attacks develop and progress will be very interesting and make me proficient at securing my server(s).