do I need to install fail2ban on CentOS
I have firewall rules set up and also denyhosts installed. do I also need to install fail2ban?
Denyhosts protects only ssh; Fail2Ban protects all daemons.
Yes, why not; fail2ban is very nice software. Fail2ban is a very good firewall for bruteforce attacks, on ftp, ssh, mail server and etc.