IPv6 global addresses are similar to IPv4 public addresses. As the name implies, they are routable on the internet. Currently IANA has assigned only 2000::/3 addresses to the global pool.
A global IPv6 address consists of two parts:
- subnet ID – 64 bits long. Contains the site prefix (obtained from a Regional Internet Registry) and the subnet ID (subnets within the site).
- interface ID – 64 bits long. typically composed of a part of the MAC address of the interface.
Here is a graphical representation of the two parts of an global IPv6 address: