IP and MAC addresses allow data to be sent and received by devices on networks. Think of it like posting a letter — without an address on the front, the postal service would not know who to deliver it to.
IP Addresses
- Every computer on a network has an IP (Internet Protocol) address
- Each IP address is unique on that network
- IP addresses are assigned to a device when it joins a network
- IP addresses allow communication between different networks
- There are two versions: IPv4 and IPv6
MAC Addresses
- Networking hardware within a computer has a MAC (Media Access Control) address
- Each MAC address is unique to the networking hardware
- MAC addresses are assigned by the device manufacturer and cannot be changed
- MAC addresses allow communication on the same network
In an exam, you may be given an address and asked to identify whether it is IPv4, IPv6, or MAC address.
IPv4 Addresses
- Four numbers (octets) separated by a dot
- Each number is in the range 0 – 255, so addresses range between 0.0.0.0 – 255.255.255.255.
- Each octet is one byte
- As the number of devices has increased, we have now used all available IPv4 addresses.
Example IPv4 Address:
193.74.211.63
IPv6 Addresses
- Eight blocks of four hexadecimal digits separated by colons – 128 bits in total
- Blocks of numbers which are the same can be shortened to one number (e.g. 0000 can be shorted to just one 0)
- IPv6 supports more devices than there are atoms on the planet, so we will never run out!
Example IPv6 Address:
2a00:23c4:d681:0000:2d80:878f:f37b:fce3
MAC Addresses
- Six blocks of two hexadecimal digits (6 bytes) separated by dashes
- Unique to each networking interface card (e.g. the Wi-Fi card), not the computer. So if a PC has Wi-Fi and Ethernet hardware, it will have two different MAC addresses
- Each MAC address is unique and cannot be changed
Example MAC Address: