1 files changed, 395 insertions, 0 deletions
diff --git a/doc/rfc/rfc2921.txt b/doc/rfc/rfc2921.txt
new file mode 100644
index 0000000..b944a15
--- /dev/null
+++ b/doc/rfc/rfc2921.txt
@@ -0,0 +1,395 @@
+
+
+
+
+
+
+Network Working Group                                            B. Fink
+Request for Comments: 2921                                         ESnet
+Category: Informational                                   September 2000
+
+
+                   6BONE pTLA and pNLA Formats (pTLA)
+
+Status of this Memo
+
+   This memo provides information for the Internet community.  It does
+   not specify an Internet standard of any kind.  Distribution of this
+   memo is unlimited.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2000).  All Rights Reserved.
+
+Abstract
+
+   This memo defines how the 6bone uses the 3FFE::/16 IPv6 address
+   prefix, allocated in RFC 2471, "IPv6 Testing Address Allocation",
+   [6BONE-TLA], to create pseudo Top-Level Aggregation Identifiers
+   (pTLA's) and pseudo Next-Level Aggregation Identifiers (pNLA's).
+
+Acknowledgements
+
+   The address formats here are contributions of various early
+   participants of the 6bone testbed project, and of the IPng and
+   NGtrans IETF working groups.
+
+Table of Contents
+
+   1.  Introduction................................................. 1
+   2.  6BONE pTLA/pNLA Format....................................... 2
+   3.  Security Considerations...................................... 6
+   References....................................................... 6
+   Author's Address................................................. 6
+   Full Copyright Statement......................................... 7
+
+1. Introduction
+
+   This memo defines how the 6bone uses the 3FFE::/16 IPv6 address
+   prefix, allocated in RFC 2471 [6BONE-TLA], to create pseudo Top-Level
+   Aggregation Identifiers (pTLA) and pseudo Next-Level Aggregation
+   Identifiers (pNLA).
+
+
+
+
+
+
+Fink                         Informational                      [Page 1]
+
+RFC 2921              6BONE pTLA and pNLA Formats         September 2000
+
+
+   The guiding specifications for IPv6 addressing relating to the 6bone
+   prefix, and the pTLA and pNLA formats, are "IP Version 6 Addressing
+   Architecture"  [ADDRARCH], and "An IPv6 Aggregatable Global Unicast
+   Address Format" [AGGR].
+
+   The purpose of creating pseudo TLA and NLA formats for the 6bone is
+   to provide a prototype of the actual TLA and NLA formats as they
+   might be used in production IPv6 networks. To do this economically,
+   using only a minimum of real production IPv6 address space, a single
+   TLA, 3FFE::/16, was reserved by the IANA (Internet Assigned Numbers
+   Authority) for testing on the 6bone. Thus it was necessary to define
+   a pretend-to-be, or pseudo, TLA and NLA structure to use under the
+   3FFE::/16 prefix.
+
+   Given the 48-bit length of the IPv6 Aggregatable Global Unicast
+   Address external routing prefix (that contains the TLA and NLA
+   identifiers), there is enough room to extend the TLA ID to contain a
+   pTLA and shorten the NLA ID to become a pNLA. This document specifies
+   this.
+
+   In early 1999, it was decided to change the 6bone's pTLA format to
+   allow greater expansion of the testbed network, thus accommodating
+   more than the original 256 pTLA-s. Thus there are now two 6bone pTLA
+   and pNLA formats. This document specifies this.
+
+2. 6BONE pTLA and pNLA Formats
+
+2.1 Original 8-bit pTLA and 24-bit pNLA Format
+
+   The original pTLA and pNLA format was intended to accommodate 256
+   pTLA-s, i.e., backbone networks carrying IPv6 transit traffic.
+
+   The original TLA and NLA ID-s as specified in [AGGR] are as follows:
+
+      | 3 |  13 |          32         |   16   |    64 bits      |
+      +---+-----+---------------------+--------+-----------------+
+      |001| TLA |       NLA ID        | SLA ID | Interface ID    |
+      +---+-----+---------------------+--------+-----------------+
+
+   The TLA value 1FFE was assigned to the 6bone, which when viewed with
+   the 3-bit format prefix in prefix notation form is 3FFE::/16.
+
+   The first 8-bits of the NLA ID space are assigned as the pTLA that
+   defines the top level of aggregation (backbone) for the 6bone. This
+   provides for 256 6bone backbone networks, or pTLA-s, and leaves a
+   24-bit pNLA ID for each pTLA to assign as needed.
+
+
+
+
+
+Fink                         Informational                      [Page 2]
+
+RFC 2921              6BONE pTLA and pNLA Formats         September 2000
+
+
+      |     16    |  8  |     24      |   16   |    64 bits      |
+      +-+---------+-----+-------------+--------+-----------------+
+      |  0x3FFE   |pTLA |     pNLA    | SLA ID | Interface ID    |
+      +-+---------+-----+-------------+--------+-----------------+
+
+   In prefix notation form the pTLA is 3FFE:nn00::/24, where nn is the
+   pTLA assignment.
+
+   The remaining NLA ID space can be used by each pTLA for their
+   downward aggregated delegation:
+
+      |  n  |      24-n bits     |   16   |    64 bits      |
+      +-----+--------------------+--------+-----------------+
+      |pNLA1|       Site         | SLA ID | Interface ID    |
+      +-----+--------------------+--------+-----------------+
+
+            |  m  |    24-n-m    |   16   |    64 bits      |
+            +-----+--------------+--------+-----------------+
+            |pNLA2|    Site      | SLA ID | Interface ID    |
+            +-----+--------------+--------+-----------------+
+
+                  |  o  |24-n-m-o|   16   |    64 bits      |
+                  +-----+--------+--------+-----------------+
+                  |pNLA3|  Site  | SLA ID | Interface ID    |
+                  +-----+--------+--------+-----------------+
+
+   The pNLA delegation works in the same manner as specified in [AGGR].
+   pTLA's are required to assume registry duties for the pNLA's below
+   them, pNLA1's for those below them, etc.
+
+2.2 New 12-bit pTLA and 20-bit pNLA Format
+
+   After it became clear that the 6bone would become a useful testbed
+   for transition, in addition to its early role as a testbed for
+   specifications and implementations, the 6bone community decided to
+   expand the size of the pTLA ID.
+
+   Several important decisions regarding this expansion of the pTLA
+   field are:
+
+   1. to leave the currently allocated 8-bit pTLA-s in use until the
+      space was needed, thus relying on a range value check to indicate
+      the new pTLA format,
+
+   2. to use a modulo 4-bit sized pTLA ID to make reverse path entry
+      into the DNS easier,
+
+
+
+
+
+Fink                         Informational                      [Page 3]
+
+RFC 2921              6BONE pTLA and pNLA Formats         September 2000
+
+
+   3. given 2. above, to keep the pTLA ID size as small as possible
+      to not restrict pNLA ID size.
+
+   Therefore, the first 12-bits of the NLA ID space are assigned as the
+   pTLA that defines the top level of aggegation (backbone) for the
+   6bone. This would eventually provide for 4096 6bone backbone
+   networks, or pTLA-s, and leaves a 20-bit pNLA ID for each pTLA to
+   assign as needed.
+
+      |     16    |   12  |   20      |   16   |    64 bits      |
+      +-+---------+-------+-----------+--------+-----------------+
+      |  0x3FFE   | pTLA  |   pNLA    | SLA ID | Interface ID    |
+      +-+---------+-------+-----------+--------+-----------------+
+
+   In prefix notation form the pTLA is 3FFE:nnn0::/28, where nnn is the
+   pTLA assignment. However, as the existing 8-bit pTLA's are being left
+   in use for the present, the nnn value starts at 0x800 for now, thus
+   yielding only 2048 pTLA's in this new format.
+
+   The remaining NLA ID space can be used by each pTLA for their
+   downward aggregated delegation:
+
+      |  n  |      20-n bits     |   16   |    64 bits      |
+      +-----+--------------------+--------+-----------------+
+      |pNLA1|       Site         | SLA ID | Interface ID    |
+      +-----+--------------------+--------+-----------------+
+
+            |  m  |    20-n-m    |   16   |    64 bits      |
+            +-----+--------------+--------+-----------------+
+            |pNLA2|    Site      | SLA ID | Interface ID    |
+            +-----+--------------+--------+-----------------+
+
+                  |  o  |20-n-m-o|   16   |    64 bits      |
+                  +-----+--------+--------+-----------------+
+                  |pNLA3|  Site  | SLA ID | Interface ID    |
+                  +-----+--------+--------+-----------------+
+
+   As with the original pTLA format, the pNLA delegation works in the
+   same manner as specified in [AGGR]. pTLA's are required to assume
+   registry duties for the pNLA's below them, pNLA1's for those below
+   them, etc.
+
+2.3 Example Format For pNLA's
+
+   An example usage of the pNLA space is given to demonstrate what is
+   reasonable and possible. It should not be assumed that this implies
+   the pNLA space must be used this way. As the new pTLA and pNLA format
+   is now the default, the example here assumes the 20-bit pNLA format.
+
+
+
+Fink                         Informational                      [Page 4]
+
+RFC 2921              6BONE pTLA and pNLA Formats         September 2000
+
+
+   The following example provides for up to 255 intermediate transit
+   ISP's (called pNLA1 below). The pNLA1 value of zero is meant to
+   indicate that there is no intermediate transit ISP between the
+   backbone pTLA network and the end user site.
+
+      |<-----20-bit pNLA ID----->|
+      |                          |
+      |  8  |       12 bits      |   16   |    64 bits      |
+      +-----+--------------------+--------+-----------------+
+      |pNLA1|      Site  ID      | SLA ID | Interface ID    |
+      +-----+--------------------+--------+-----------------+
+
+   Intermediate transit networks (pNLA1's) would assign uniques Site
+   ID's for eachend user site served.
+
+   As an example of this, assuming a backbone pTLA of 0x800, no
+   intermediate transit ISP (thus a pNLA1 of 0x00) and a sequential site
+   ID (with start at the right edge numbering) of 0x0001, the routing
+   prefix for the first site would look like:
+
+            3FFE:8000:0001/48
+     6bone _|||| |||| ||||___site
+                 |||| |
+     b/b site____|||| |
+                    | |
+     transit________|_|
+
+   Another example of this usage, assuming the same backbone pTLA1 of
+   0x800 and an intermediate transit ISP under it (numbering from the
+   left edge) with an NLA1 of 0x80, and a sequential site ID of 0x0001,
+   the routing prefix for the first site connected would look like:
+
+            3FFE:0180:0001/48
+     6bone _|||| |||| ||||___site
+                 ||||
+     b/b site____||||
+                   ||
+     transit_______||
+
+   Note 1: the two sites numbered 0x001 in the above examples are really
+   two different sites as their pNLA1 authority above them is different
+   (i.e., in the first case no transit exists thus the site is directly
+   connected to the pTLA backbone ISP, and in the second case the site
+   is directly connected to intermediate transit ISP 0x80).
+
+   Note 2: there would be nothing to prevent an pNLA1 transit site from
+   further allocating pNLA's below, but that becomes the policy of the
+   pTLA and pNLA's above them to work out.
+
+
+
+Fink                         Informational                      [Page 5]
+
+RFC 2921              6BONE pTLA and pNLA Formats         September 2000
+
+
+   Note 3: The 6bone registry, which is a RIPE-style database for
+   documenting IPv6 sites connected to the 6bone, has an "inet6num"
+   object to allow documentation of all IPv6 addresses allocated.
+
+3.  Security Considerations
+
+   IPv6 addressing documents do not have any direct impact on Internet
+   infrastructure security.
+
+References
+
+   [ADDRARCH]  Hinden, R. and S. Deering, "IP Version 6 Addressing
+               Architecture", RFC 2373, July 1998.
+
+   [AGGR]      Hinden, R., O'Dell, M. and S. Deering, "An IPv6
+               Aggregatable Global Unicast Address Format", RFC 2374,
+               July 1998.
+
+   [HARDEN]    Rockell, R. and R. Fink, "6Bone Backbone Routing
+               Guidelines", RFC 2772, February 2000.
+
+   [KEYWORDS]  Bradner, S., "Key words for use in RFCs to Indicate
+               Requirement Levels", BCP 14, RFC 2119, March 1997.
+
+   [6BONE-TLA] Hinden, R., Fink, R. and J. Postel, "IPv6 Testing Address
+               Allocation", RFC 2471, December 1998.
+
+Author's Address
+
+   Bob Fink, ESnet
+   Lawrence Berkeley National Lab
+   MS 50A-3111
+   1 Cyclotron Road
+   Berkeley, CA 94720
+   USA
+
+   Phone: +1 510 486 5692
+   Fax:   +1 510 486 4790
+   EMail: fink@es.net
+
+
+
+
+
+
+
+
+
+
+
+
+Fink                         Informational                      [Page 6]
+
+RFC 2921              6BONE pTLA and pNLA Formats         September 2000
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2000).  All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works.  However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assigns.
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+Acknowledgement
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Fink                         Informational                      [Page 7]
+