1. IP Addressing The in’s and out’s

2. Lesson Objectives O Know the purpose of an IP address O Understand the structure of an IP address

3. Basics of IP’s O You can think of an IP address as a letter. O On the letter there will be an address and postcode O The postcode is a high precision location system to identify houses in the UK (and world)

4. An IP address O 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.

5. Binary Version O 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

6. Challenge What’s the maximum number of addresses you can get from this type of address system?

7. Reserved Addresses O 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 – 255.255.255.255 O Network address – 0.0.0.0 O Broadcast address is a way in which to contact all of the computers in a group O Network address is a default address that scoops up any messages to an undefined IP

8. IP’s Running out O 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 has 340 282 366 920 938 463 463 374 607 431 768 211 456 unique addresses IPv6 Address 2001:0db8:85a3:0042:1000:8a2e:0370:7334