IP Address
- An IP (Internet Protocol) address is a unique numerical identifier assigned to devices connected to the internet
- IP addresses are used to identify and locate devices on the internet
- This allows data to be sent and received between devices
- An IPv4 address is four numbers separated by a full stop
- Each number is a byte and range between 0-255
- There are over 4 billion unique addresses using the IPv4 system
- For example, an IPv4 address might look like this: 192.164.3.1
- Routers and gateways have a unique public address
- Public addresses are assigned by your internet service provider and is the IP address for the network
- Public addresses are often static addresses meaning they do not change
A diagram showing how Private and Public IP addresses are used to identify devices on the Internet and within a LAN
- A router can assign private IP addresses to devices connected within its network
- These are often dynamic IP addresses meaning they can change
- Dynamic addresses are assigned from a list of available addresses at the time they are required
- The IP4 system is running out of possible addresses due to the enormous increase in networked devices
- A new system called IPv6 has been developed. It provides enough unique addresses for every networked device on the planet
- IPv6 uses a 128 bit address
- Digits are organised into eight groups
- Each group is made up of four hexadecimal digits
- For example bb43:ff3f:0000:549b:e43e:db84:1f1f:0b9e
Worked example
Give two characteristics of an IP address
[2]
Any 2 of:
- A unique address [1]
- Can be public or private [1]
- Can be static or dynamic [1]
- IPv4 has four groups of digits [1]
- Each number is between 0-255 [1]
- and separated by a full stop [1]
- IPv6 has eight groups of digits [1]
A comparison of IPv4 and IPv6 IP addresses
|
|
|
|
32-bit address |
128 bit address |
|
Four groups of denary digits separated by a full stop |
Eight groups of four hexadecimal digits separated by a colon |
|
Over 4.3 billion unique addresses |
Almost infinite amount of unique addresses |
Worked example
Explain the difference between a private and a public IP address
[4]
Any 4 of:
- A private IP address is not accessible from the internet [1]
- and is used to identify a device within a local area network [1]
- A public IP address is used to identify a device on the internet [1]
- Public IP addresses are assigned by an internet service provider (ISP) [1]
- Public IP addresses are unique [1]
- Public IP addresses can be accessed from anywhere on the internet [1]
- Public IP addresses allow devices to communicate with each other across different networks [1]
