A Flexible Method for Managing the Assignment of Bits of an IPv6 Address Block

This document proposes a method to manage the assignment of bits of an IPv6 address block or range. When an organisation needs to make an address plan for its subnets or when an ISP needs to make an address plan for its customers, this method enables the organisation to postpone the final decision on the number of bits to partition in the address space they have. It does it by keeping the bits around the borders of the partition to be free as long as possible. This scheme is applicable to any bits addressing scheme using bits with partitions in the space, but its first intended use is for IPv6. It is a generalization of RFC 1219 and can be used for IPv6 assignments.