General IT

IPv6 – What do I need to know

IPv6 has been around a lot longer than you may think. IPv6 became a Draft Standard for the IETF in December 1998, who subsequently ratified it as an Internet Standard on 14 July 2017.

We’re reaching the point we need to move over to IPv6 so I decided to look into how it works in more detail. It appears a lot more simple than I was expecting.

I first checked my home network to see if I was able to use IPv6, and found out it was already enabled.
To check if you are using IPv6, simply run ipconfig from a command line.

IPv6 results from ipconfig /all command

If you can see an IPv6 address you are IPv6 enabled on your internal network.

To check if you have IPv6 on your internet connection just Google “What’s my IP”.
If you see an address starting with 4 characters and a : , such as 2a01: then you are IPV6 enabled for the internet. If you see just numbers separated by full stops (,) then you just have IPv4 on the internet.

You can see the difference in IPV6 and IPv4 addresses in the screenshot above.

How does IPv6 work?

IPv6 works on a similar basis to IPv4 but in order to accommodate more addresses, IPv6 uses 128 bits instead of 32bits for IPv4.

Other differences are hexadecimal is used instead of binary, and colons (:) instead of points (.).

The final difference is that because IPv6 addresses are longer they have several rules to shorten them. A group of 4 zero’s ie :0000: can be shortened to :0: or even::

Types of IPv6 addresses

There are 12 types of IPv6 address as reported by RIPE (referenced here). However, there are only 3 that are commonly used, the others are reserved for examples and documentation, etc.

Local Link addresses – These are non-routed local addresses and start with fe80::. This is the equivalent of a 169.254.0.x in IPv4 terms.

Unique Local Addresses – These are routed local addresses and start with prefixes from fc00: to fdff:. This is the equivalent of a local internal network and the IPv4 equivalent would be a 192.168.0.0, 172.16.0.0. or 10.0.0.0 network.

Global Unicast Addresses – These are internet routed addresses and are in the 2000::/3 range. These addresses are listed in the WHOIS lookup and are equivalent to your Public Internet address.

Local Loopback Address – The other address worth mentioning is ::1 which is the local loopback address, the equivalent of IPv4 127.0.0.1.

If this has helped, or you have a question please let me know in the comments section below.

Thanks

Ian

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