Bind 9 Administrator Reference Manual

Appendix A. Appendices
8 Reserved bits
24 bits for Next Level Aggregators. This allows organizations with a TLA to hand out portions of their IP
space to client organizations, so that the client can then split up the network further by filling in more
NLA bits, and hand out IPv6 prefixes to their clients, and so forth.
There is no particular structure for the Site topology section. Organizations can allocate these bits in any
way they desire.
The Interface Identifier must be unique on that network. On ethernet networks, one way to ensure this is
to set the address to the first three bytes of the hardware address, "FFFE", then the last three bytes of the
hardware address. The lowest significant bit of the first byte should then be complemented. Addresses
are written as 32-bit blocks separated with a colon, and leading zeros of a block may be omitted, for
example:
3ffe:8050:201:9:a00:20ff:fe81:2b32
IPv6 address specifications are likely to contain long strings of zeros, so the architects have included a
shorthand for specifying them. The double colon (‘::’) indicates the longest possible string of zeros that
can fit, and can be used only once in an address.
A.4. Bibliography (and Suggested Reading)
A.4.1. Request for Comments (RFCs)
Specification documents for the Internet protocol suite, including the DNS, are published as part of the
Request for Comments (RFCs) series of technical notes. The standards themselves are defined by the
Internet Engineering Task Force (IETF) and the Internet Engineering Steering Group (IESG). RFCs can
be obtained online via FTP at ftp://www.isi.edu/in-notes/RFCxxx.txt (ftp://www.isi.edu/in-notes/)
(where xxx is the number of the RFC). RFCs are also available via the Web at http://www.ietf.org/rfc/.
Bibliography
Standards
[RFC974] C. Partridge, Mail Routing and the Domain System, January 1986.
[RFC1034] P.V. Mockapetris, Domain Names — Concepts and Facilities, November 1987.
108