[expert] IPtables question

[Stephen Boulet]

I'm wondering about the functioning of IPTables on my LM8 install.

I have two ethernet cards: eth0 is external and eth1 is internal.

Using nmap, I get:

   [root@mozart root]# nmap -sT <my external IP>:
   6000/tcp   open        X11
 
among other entries. When I do:

   iptables -A INPUT -p tcp --destination-port 6000 -i eth0 -j DROP

the command is accepted, but nmap still shows port 6000 as being open. Any 
idea what's going on?