Sharing internet connection in Linux

In this article I want to share about "how to share internet connection in Linux", in my condition, internet come from usb modem interface (ppp0) and I want to share with another network interface, wlan0 interface.  To share internet connection in Linux, you must following some steps bellow:

1. Enable IP Forward
   

   
   #echo 1 > /proc/sys/net/ipv4/ip_forward
   

   
   



2. Clear ip table
   

   #iptables -F -t nat

   
   


3. Using ip tables to create internet packet routing
   

   #iptables --table nat --append POSTROUTING --out-interface ppp0 -j MASQUERADE
   #iptables --append FORWARD --in-interface wlan0 -j ACCEPT

   
   


4. Restart network
   

   /etc/init.d/networking restart

   
   

Note:
I'm using Ubuntu 10.10 (Maverick) 32 bit