IPv6 Addressing

Many items have changed with IPv6 but none as dramatically as the addressing scheme.    Even before you begin your transition, setting up your addressing profile will be critical.  The very large IPv6 address space supports a total of 2128 (about 3.4×1038) addresses—or approximately 5×1028 (roughly 295) addresses for each of the roughly 6.8 billion (6.8×109) people alive in 2010.[11] In another perspective, this is the same number of IP addresses per person as the number of atoms in a metric ton of carbon.

While these numbers are impressive, it was not the intent of the designers of the IPv6 address space to assure geographical saturation with usable addresses. Rather, the longer addresses allow a better, systematic, hierarchical allocation of addresses and efficient route aggregation.  What you learned and used with IPv4 may not work as you might think with IPv6.    With IPv6, changing the prefix announced by a few routers can in principle renumber an entire network since the host identifiers (the least-significant 64 bits of an address) can be independently self-configured by a host.

Come and begin the journey to IPv6 with an understanding of the IPv6 addressing scheme!

Tracks: Network Support and Management