can someone verify if the following commands are correct given the
situations below:

1. rule to allow anyone on the internal network can access the Web
server on the DMZ (10.0.20.3) as well as the external web sites

iptables -A OUTPUT -s any -d 10.0.20.3 -p HTTP -j ACCEPT
iptables -A OUTPUT -s any -d any -p HTTP -j ACCEPT

2. rule that prevents hosts on the internet from accessing internal
hosts (10.0.20.0 network) directly using the WWW service

iptables -A INPUT -s any -d 10.0.20.0 -p HTTP -j DROP

ok...ok... this is a homework...we run the XUBUNTU in the class, learn
to configure the iptables (in short time - hence i still have no idea
what is this still all about) and we got this homework.