question in iptables
 

Hi everyone,
I am a beginner in Linux and in the networking but I really want to learn all these stuff.
I am trying to do a small network contains three machines. I need to allow a machine X to send messages to machine Y through Z. I should allow all traffic from the X net (say for example from ip 10.1.1.0) to the Y (say ip 20.2.2.0) net in Z iptables. I wrote these rules but I do not know if they are right or wrong. Can any one tell me if these are right, or give me a good reference to read, I will appreciate it so much.
Thanks

iptables –F
iptables –P INPUT DROP
iptables –P FORWARD DROP
iptables –A FORWARD –i eth0 –p ANY –j ACCEPT
iptables –A FORWARD –d 20.2.2.0 –p tcp –-dport 22 –j ACCEPT

This is a kick ass guide which actually teached me about how iptables works and I still check it for references until nowadays:
http://iptables-tutorial.frozentux.n...-tutorial.html

You can also check this example:
http://wiki.linuxquestions.org/wiki/..._a_gateway/nat


Hopefully you will get it clear after you read the links stated above.