I've always moved my server ports to the 10,000+ range. The number of connections is trivial. In conjunction with the following, I've had virtually no issues:

I've always moved my server ports to the 10,000+ range. The number of connections is trivial. In conjunction with the following, I've had virtually no issues: Port 22222 #Easy to remember, rarely hit. Even if it does get hit, it takes them a little longer to scan up to this range. Move it higher if you want. Protocol 2 #NO EXCEPTIONS! LoginGraceTime: 60 #seconds. If you need more than 60 seconds, you're probably doing it wrong. Change to 30 if your host is fast. PermitRootLogin No #self explanatory. No means no. AllowUsers jefe78 otherguy #this should help if you use obscure user names Now, combine that with denyhosts http://centoshelp.org/security/denyhosts/ http://centoshelp.org/security/denyhosts/ and some really strict configs and you should be better off than you were.