[Techtalk] iptables to block a single host...

[Walt]

I have a particular host harassing my server, but
they're on a DSL connection with a fairly frequently
changing IP. So, I was going to try to block them
based on their domain information using this command:

/sbin/iptables -A INPUT -p TCP -s *.balt.east.verizon.net -d 0/0 -j DROP

but it says host/network 'balt...net' not found

How can I modify this...?
Can I even do what I'm aiming to?

Thanks...,
Walt

-~


     Nothing in the world annoys a person more than
     not being taken seriously.
                         Palacio Valdes