Networking and TCP / IP

Introduction

So what does 192.0.2.44 mean? It’s an Internet Protocol (IP) address which is used by the internet to communicate between hosts.

IP is part of TCP/IP, which is the protocol suite responsible for routing data round the internet.

A “Host” is just a device connected to the internet, it can be a Server, PC, network printer or IOT device, in fact just about anything.

TCP/IP = Transmission Control Protocol / Internet Protocol

But….

TCP/IP is comprised of more than TCP and IP.

It actually has:-

TCP = Transmission Control Protocol UDP = User Datagram Protocol ICMP = Internet Control Message Protocol

IP = Internet Protocol

So maybe TCP/IP should be TCP/UDP/ICMP/IP !!

Most TCP/IP traffic is referred to as IPv4, but IPv6 is already in use and growing.

IPv6 was devised to overcome a shortage in IPv4 addresses.

So where did IPv1,2,3 an IPv5 end up?

IPv1,2 and 3 were experimental, IPv4 was the first production version.

IPv5 was called Internet Stream Protocol, it too was experimental and was never used in production.

TCP/IP is not Ethernet!

In the OSI stack:-

TCP/IP is a “Layer 3” protocol.

Ethernet is a “Layer 2” protocol

So whilst ethernet is the most common way To carry IP traffic, it can be carried on:-