
284 Part Two • IPv6 Protocols
a random component and the globally unique interface identifier (when
available), to increase the likelihood that different nodes generate different
sequences.”
16.4 Renumbering
As we’ve seen in Part I, the practice of allocating addresses on a permanent
or semipermanent basis, especially when allocations are made by ISPs
rather than by central authorities, has caused an ongoing explosion in
the size of nondefault routing tables. When an ISP allocates a portion of
its own allocation, packets addressed to the ISP’s customers are easily
aggregatable. However, when a customer changes ISPs, the customer must
either give up his ...