Книга: Iptables Tutorial 1.2.2
This chapter has given some small insight into why this document was written and how it was written. It also explained some common terms used throughout the document.
The next chapter will bring up a rather lengthy introduction and repetition to TCP/IP. Basically this means the IP protocol and some of its sub-protocols that are commonly used with iptables and netfilter. These are TCP, UDP, ICMP and SCTP. SCTP is a rather new standard in comparison to the other protocols, hence quite a lot of space and time has gone into describing this protocol for all of those who are still not quite familiar with it. The next chapter will also discuss some basic and more advanced routing techniques used today.