====== Networking and TCP / IP ======

===== Introduction =====


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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.

^ Protocol ^ Maximum number of hosts
| IPv4 | 4,294,967,296 |
| IPv6 | 340,282,366,920,938,463,463,374,607,431,768,211,456 |

 
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.

https://rednectar.net/2012/05/24/just-how-many-ipv6-addresses-are-there-really/



===== TCP/IP and Ethernet =====

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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:-


==== Token Ring ====

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==== Serial lines ====

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==== ATM (Asynchronous Transport Mode) ====


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