In this module we are going to cover various aspects of IP. We are going to start by looking at one of the most common protocol stacks: The OSI protocol stack and look at how communications is broken down into seven core areas. We are then going to compare the seven layer OSI stack with the TCP/IP protocol stack. Then, we are going to cover numbering systems and see how to translate between decimal and binary. | IP Concepts Security Essentials The SANS Institute IP Concepts - SANS 2001 1 Hello welcome to IP Concepts. This is one of two modules on the subject of TCP IP. Since the TCP IP protocol suite is fundamental to any network that is connected to the Internet in order to secure TCP IP based networks one must understand how they work and why they work. In this module we are going to start by looking at the IP protocol and then in the second module we will cover the other protocols that reside in the TCP IP protocol suite. Lets jump in and start looking at how IP works. 2 - 1 Objectives Protocol stacks Numbering systems Packets how is data transmitted IP Addressing IP Concepts - SANS 2001 2 In this module we are going to cover various aspects of IP. We are going to start by looking at one of the most common protocol stacks The OSI protocol stack and look at how communications is broken down into seven core areas. We are then going to compare the seven layer OSI stack with the TCP IP protocol stack. Then we are going to cover numbering systems and see how to translate between decimal and binary. Since humans operate on a base 10 numbering system and computers operate on a base 2 it is important that you understand how to translate between the two systems. Then we will cover how data is put into packets and sent across the wire. IP which is the fundamental protocol of TCP IP will then be covered in-depth looking at various aspects of the header. We will finish the section by looking at IP addresses and how they are broken down into two pieces A network and a host portion. Now lets start by looking at what a protocol stack is. 2 -2 Protocol Stacks Divide network communications into layers Each layer provides service to the layer above and receives service from the layer below Divide task of communication into pieces for easier implementation IP Concepts - SANS 2001 3 Having all these protocols is nice but how does information actually get from one place to another In order
