IPv4, IPv6 and MAC Addresses

MAC Addresses

Media Access Control addresses (aka Physical Addresses) are the addresses used to send data between devices on a LAN or private network. They are hard coded into a device by the manufacturer and cannot be changed*.

MAC addresses are a series of 12 Hexadecimal digits – e.g  34:E1:B2:55:71:00:C1

MAC addresses are used at the Data Link Layer of the OSI model.

* Though they can be spoofed by hackers.

Internet Protocol Version 4 Addresses

IPv4 is the legacy version of IP addressing that is slowly being phased out, starting about 15 years ago. Most devices now use IPv6 but many legacy devices still rely on IPv4 so it remains part of the internet.

IPv4 uses 32 bit addresses, using written in decimal form split into 4 sections separated by a full stop. For example 192.168.1.35

When the internet was first invented 32 bits  (4 billion addresses) was more than enough for every device to have an address, however after the invention of PCs, smart phones and smart devices, the number of available IP addresses was eventually exhausted. IPv6 resolves this problem fully with 128 bit addresses, however in the meantime a combination of public/private IP addresses and IP address pools act as a workaround until IPv4 legacy devices are removed from the system.

Internet Protocol Version 6 Addresses

IPv6 Addresses are the newer version of IP addressing that has almost fully replaced IPv4. IPv6 use 128 bit addresses that are usually written in hexadecimal. e.g. – 45B2 : 0070 : DD32 : 0023 : 7100 : 2310: 00FF : CC46

IPv6 addresses can be long and so it is important to compress the IP address where possible to make it easier to read. The video below explains how this can be done.

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