htaccess/banning help please

I'm pretty uneducated when it comes to utilizing .htaccess.

I have a few problem users on my website whom I have banned by thier IPs. However, most of these trolls are dialup users.

With thier IPs I am able to find host names. Two questions:

1. Are host names static?
2. Would it be possible to ban via host names using htaccess?

Thanks for any guidance.

1) An IP maybe DNS lookup'able to ONE hostname, just ONE. Conversely, thousands of hostnames can be configured to point to the same IP.

2) Start here

Thanks a lot man.

I always new there were trolls, but had no idea actually how many there were until I made my forums live.