I'm running a hobby Debian sever hosting a few web sites, software repositories, and some other apps. There are tons of all kinds of network security enhancement tools available. Firewalls, hardening patches, intrusion preventors… Obviously no one needs all of these. I was wondering, what are the most essential ones, what should a normal user (i.e. not interested in becoming security expert) use?
I'm aware that no tool replaces good administration, and that most problems arise from poor passwords, non-patched apps, and so on. But if installing some clever tool gives a bit of extra security, then I'm interested.
Update: Debian is apparently quite secure right out of the box, and stays secure as long as its user keeps the system up to date and doesn't do anything stupid. That's good, of course. There's not much that add-on tools could actually add, but here are the suggestions with more than one vote so far:
- Firewall (Shorewall/IPtables)
- "Bruteforce login limiter" (fail2ban)
- Rootkit checker (chkrootkit)