IP AddressingThe in’s and out’s

Lesson Objectives

O Know the purpose of an IP address

O Understand the structure of an IP address

Basics of IP’sO You can think of an IP address as a

letter.O On the letter there will be an address

and postcodeO The postcode is a high precision

location system to identify houses in the UK (and world)

An IP addressO Every machine that needs to be

connected to the internet or on a network will be given an IP address

216.27.61.137

O To make it easier for us to read the address, they are broken up into 4 blocks.

Binary VersionO As computers deal in 1’s and 0’s the

IP address will look something like this:

11011000.00011011.00111101.10001001

Each block is a byte (8 bits), giving you 256 unique addresses per block. A block is called an octet

Challenge

What’s the maximum number of addresses you can get from this

type of address system?

Reserved AddressesO Out of the 4,294,967,296 unique addresses

that you can have using IPv4 there are a couple of addresses that are unavailable to use publically.

O Broadcast address – 255.255.255.255O Network address – 0.0.0.0O Broadcast address is a way in which to

contact all of the computers in a groupO Network address is a default address that

scoops up any messages to an undefined IP

IP’s Running outO We are getting close to running out

of IPv4 addresses!O http://www.bbc.co.uk/news/

technology-19600718

O The next option is IPv6 and it has340 282 366 920 938 463 463 374 607 431 768 211 456 unique addresses

IPv6 Address2001:0db8:85a3:0042:1000:8a2e:0370:7334