[olug] help with iptables firewall

[Ryan Stille]

I have a server that has 1 physical network interface.  It has an 
internal IP address on our network.  I want to add a public IP as an ip 
alias, then we'll set that IP up in our router as a DMZ.  So I need to 
setup a firewall on the local machine to block most ports on the public 
IP.  I've come up with this:

iptables -F
iptables -A INPUT -p TCP -d $PUB_IP -s 0/0 --destination-port 80 -j ACCEPT
iptables -A INPUT -p ALL -d $PUB_IP -j DROP

It appears to work.  Am I missing something?

Thanks,
-Ryan