Beginnig Firewall

[mrparadox]

My team has decided to make a simple ip filtering firewall.But do not know where to start. I have the following questions,can anyone answer these: -
1. How can ip filtering be implemented as the standard c++ library does not support it?
2. What is needed to start this project?

[simo110]

You can review other product's source from sourceforge.There are many open source firewall.
http://sourceforge.net/search/?type_of_search=soft&words=IP+filter