Take the 2-minute tour ×  I am trying to understand how firewall
works in linux... I have read documentation but i am not sure
about some things....  Netfilters is included in the modern
kernels which allows you using hooks to monitor packages without
changing their content.  Iptables they say that it is a software
that uses netfilter and ip_tables module maybe.. My questions
are....    • Does IPTables userspace software register any hook
?   • What does ip_table module do?   • Who does the processing
iptables or the module ?   • What things IPtable do ?(Just
manages the rules in memory?? or it has hooks and proccesses the
traffic?)? share|improve this question add comment  3 Answers
up vote 3 down vote accepted   netfilter is a set of hooks
sprawled throughout the networking code in the kernel. This
means that if a piece of code is about to do something
significant (we'll call it X), it calls a function that says
"I'm about to do X". That function would then notify any other
interested parties via a registe