5. Updating RFC 7400

この文書は IPv6 Neighbor Discovery と関連する 6LoWPAN/RPL 仕様を更新し, ノードが近隣ルータへ IPv6 prefix を登録できるようにします. 重要なプロトコル詳細は RFC 原文の形で以下に保持します.

5.  Updating RFC 7400

   This specification updates "6LoWPAN-GHC: Generic Header Compression
   for IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs)"
   [RFC7400] by defining a new capability bit for use in the 6CIO.
   [RFC7400] was already extended by [RFC8505] for use in IPv6 ND
   messages.

   The new "Registration for prefixes supported" (F) flag indicates to
   the 6LN that the 6LR (1) accepts IPv6 prefix registrations as
   specified in this document, (2) will ensure that packets for the
   addresses that match this prefix will be routed to the 6LNs that
   registered the prefix, and (3) will ensure that the route to the
   prefix will be redistributed if the R flag is set to 1.

   Figure 1 illustrates the F flag in its position (16, counting 0 to 47
   in network order in the 48-bit array).

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Type      |   Length = 1  | Experimental  |X|A|D|L|B|P|E|G|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |F|                         Reserved                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 1: New Capability Bit in the 6CIO

   New Option Field:

   F:  1-bit flag, set to 1 to indicate "Registration for prefixes
      supported"