User:NeddySeagoon/IPv6

Overview
This page helps you decide if you really want to add IPv6 and if you do, how to go about it.

Your ISP
Your ISP has just arrived in the 21st century and offered you a native IPv6 connection. A native IPv6 connection is not required, since its perfectly possible to tunnel IPv6 over IPv4. 'Tunnel brokers' have been around for years. Tunnelling is not described here.

Range of Addresses
IPv4 allows at most 2^32 different IP addresses. IPv6 allows 2^128 different IP addresses.

Some tricks have been used to expand IPv4 such as Network Address Translation (NAT). This allows several internet connected devices to share a single public IP. For example, IP addresses in the 10.0.0.0/8 range are reserved for use behind NAT, as are 192.168.0.0/16 and others. This works as far as it goes but has some limitations.

If you don't understand the /8 and /16 concepts, read up about them now. IPv6 uses them exclusively. There is no more netmask.

Public IP Addresses
With IPv4, NAT provided a degree of protection against bad things coming in from the internet. Running a firewall was still a good thing, even if you are not paranoid.

With IPv6 all IP addresses are public. The concept of NAT does not exist. This means that if you are going to deploy IPv6 you either need a boundary IPv6 firewall or each IPv6 enabled device needs its own firewall.

Switching Over to IPv6
Switching to IPv6 only is not yet an option. At the time of writing the rest of the internet isn't there. If you want to use IPv6 it will be in addition to, not in place of your existing IPv4 setup. The two use completely different tools and are almost completely unaware of one another.