Locking down UDP ports

[Martin Radvany]

I have a Linux box running Red Hat 7.0 as a firewall.  I 
used a scanner at www.hackerwacker.com to scan the 
machine. All TCP ports were closed, as expected, but 
many UDP ports were open and listed as "danger 
items," ripe for hacker exploits. 

I can not seem to find any information on how to 
disable these ports.