rfc2909.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

      not considered as claims that have to be compared)

   o  timestamp when the claim was initiated

   o  the claimed prefix and lifetime

   o  MASC Identifier of the node that originated the claim

   When two claims are compared, first the type is compared based on the
   following precedence:

   PREFIX_IN_USE > CLAIM_DENIED > CLAIM_TO_EXPAND > NEW_CLAIM

   If the type is the same, then the timestamps are used to compare the
   claims.  In practice, two claims will have the same type if the type
   is either NEW_CLAIM (ordinary collision) or PREFIX_IN_USE (signal for
   a clash).  When the timestamps are compared, the claim with the
   smallest, i.e. earliest timestamp wins.  If the timestamps are the
   same, then the claim with the smallest Origin Node Identifier wins.

5.2.  Renewing an Existing Claim

   The procedure for extending the lifetime of prefixes already in use
   is the same as claiming new space (see Section 5.1), except that the
   claim type must be CLAIM_TO_EXPAND, while the Address and the Mask of
   the claim (see Section 7.3) must be the same as the already allocated
   prefix.  If the Claim-Timer expires and there is no collision, the
   desired lifetime is assumed.

5.3.  Expanding an Existing Prefix

   The procedure for extending the lifetime of prefixes already in use
   is the same as claiming new space (see Section 5.1), except that the
   claim type must be CLAIM_TO_EXPAND, while the Address and the Mask of
   the claim (see Section 7.3) must be set to the desired values.  If
   the Claim-Timer expires and there is no collision, the desired larger
   prefix is associated with the local domain.








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5.4.  Releasing Allocated Space

   If the lifetime of a prefix allocated to the local domain expires and
   the domain does not need to reuse it, all resources associated with
   this prefix are deleted and no further actions are taken.  If the
   lifetime of the prefix has not expired, and if no subranges of that
   prefix have being allocated for local usage or by some of the
   children domains, the space may be released by sending a withdraw
   message to the parent domain, all known siblings with the same
   parent, and all internal peers.

6.  Constants

   MASC uses the following constants:

   [PORT_NUMBER]
      2587.  The TCP port number used to listen for incoming MASC
      connections, as assigned by IANA.

   [WAITING_PERIOD]
      The amount of time (in seconds) that must pass between a NEW_CLAIM
      (or CLAIM_TO_EXPAND), and a PREFIX_IN_USE for the same prefix.
      This must be long enough to reasonably span any single inter-
      domain network partition.  Default: 172800 seconds (i.e. 48
      hours).

   [INITIATE_CLAIM_DELAY]
      The amount of time (in seconds) a MASC node must wait before
      initiating a new claim or a claim for space expansion. This must
      be a random value in the interval (0, [INITIATE_CLAIM_DELAY]).
      Default value for [INITIATE_CLAIM_DELAY]: 600 seconds (i.e. 10
      minutes).

   [TLD_ID]
      The Parent Domain Identifier used by a Top-Level Domain (which has
      no parent). Must be 0.

   [HOLDTIME]
      The amount of time (in seconds) that must pass without any
      messages received from a remote node before considering the
      connection is down.  Default: 240 seconds (i.e. 4 minutes).










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7.  Message Formats

   This section describes message formats used by MASC.

   Messages are sent over a reliable transport protocol connection.  A
   message is processed only after it is entirely received.  The maximum
   message size is 4096 octets.  All implementations are required to
   support this maximum message size.

7.1.  Message Header Format

   Each message has a fixed-size (4-octets) header.  There may or may
   not be a data portion following the header, depending on the message
   type.  The layout of these fields is shown below:

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Length               |      Type     |   Reserved    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length:
      This 2-octet unsigned integer indicates the total length of the
      message, including the header, in octets.  Thus, e.g., it allows
      one to locate in the transport-level stream the start of the next
      message.  The value of the Length field must always be at least 4
      and no greater than 4096, and may be further constrained,
      depending on the message type.  No "padding" of extra data after
      the message is allowed, so the Length field must have the smallest
      value required given the rest of the message.

   Type:
      This 1-octet unsigned integer indicates the type code of the
      message.  The following type codes are defined:

            1 - OPEN
            2 - UPDATE
            3 - NOTIFICATION
            4 - KEEPALIVE

   Reserved:
      This 1-octet field is reserved.  MUST be set to zero by the sender,
      and MUST be ignored by the receiver.








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7.2.  OPEN Message Format

   After a transport protocol connection is established, the first
   message sent by each side is an OPEN message.  If the OPEN message is
   acceptable, a KEEPALIVE message confirming the OPEN is sent back.
   Once the OPEN is confirmed, UPDATE, KEEPALIVE, and NOTIFICATION
   messages may be exchanged.

   The minimum length of the OPEN message is 20 octets (including
   message header).  In addition to the fixed-size MASC header, the OPEN
   message contains the following fields:

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Version    |R| AddrFam |Rol|           Hold Time           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Sender Domain Identifier    (variable length)         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Sender MASC Node Identifier (variable length)         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Parent's Domain Identifier  (variable length)         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                     (Optional Parameters)                     |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Version:
      This 1-octet unsigned integer indicates the protocol version
      number of the message.  The current MASC version number is 1.

   R bit:
      This 1-bit field is reserved.  MUST be set to zero by the sender,
      and MUST be ignored by the receiver.

   AddrFam:
      This 5-bit field is the IANA-assigned address family number of the
      encoded prefix [IANA].  These include (among others):

      Number    Description
      ------    -----------
         1      IP (IP version 4)
         2      IPv6 (IP version 6)







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   My Role (Rol):
      This 2-bit field indicates the proposed relationship of the
      sending system to the receiving system:
         00 = INTERNAL_PEER (sent from one internal peer to another)
         01 = CHILD (sent from a child to its parent)
         10 = SIBLING (sent from one sibling to another)
         11 = PARENT (sent from a parent to its child)

   Hold Time:
      This 2-octet unsigned integer indicates the number of seconds that
      the sender proposes for the value of the Hold Timer.  Upon receipt
      of an OPEN message, a MASC speaker MUST calculate the value of the
      Hold Timer by using the smaller of its configured Hold Time for
      that peer and the Hold Time received in the OPEN message.  The
      Hold Time MUST be either zero or at least three seconds.  An
      implementation may reject connections on the basis of the Hold
      Time.  The calculated value indicates the maximum number of
      seconds that may elapse between the receipt of successive
      KEEPALIVE and/or UPDATE messages by the sender.  RECOMMENDED value
      is [HOLDTIME] seconds.

   Sender Domain Identifier:
      A globally unique identifier.  Its length is determined based on
      the Address Family, and should be treated as an unsigned integer
      (e.g. a 4-octet integer for IPv4, or a 16-octet integer for IPv6),
      but must be at least 4 octets long.  It should be set to the
      Autonomous System number of the sender, but the network unicast
      prefix address is also acceptable.

   Sender MASC Node Identifier:
      This field's length and format are same as the Sender Domain
      Identifier field, and indicates the MASC Node Identifier of the
      sender.  A given MASC speaker sets the value of its MASC Node
      Identifier to a globally-unique value assigned to that MASC
      speaker (e.g., an IPv4 or IPv6 address).  The value of the MASC
      Node Identifier is determined on startup and is the same for every
      MASC session opened.

   Parent's Domain Identifier:
      This field's length and format are same as the Sender Domain
      Identifier field, and is set to the Domain Identifier of the
      sender's parent (e.g. the parent's Autonomous System number, or
      network prefix address), or is set to [TLD_ID] if the sender is a
      TLD.  Used only when Rol is INTERNAL_PEER or SIBLING, otherwise is
      ignored.  This field is used to determine the common parents
      between siblings, to associate each sibling-to-sibling connection
      with a particular parent, and to discover TLD-related




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      configuration problems among internal peers.  If a non-TLD node
      does not know yet the Domain ID of any of its parents, it can use
      its own Domain ID in the OPEN messages to its internal peers.

   Optional Parameters:
      This field may contain a list of optional parameters, where each
      parameter is encoded as a <Parameter Length, Parameter Type,
      Parameter Value> triplet.  The combined length of all optional
      parameters can be derived from the Length field in the message
      header.

       0                   1
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...
      |  Parm. Length |  Parm. Type   |  Parameter Value (variable)
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...

      Parameter Length is a one octet field that contains the length of
      the Parameter Value field in octets.  Parameter Type is a one
      octet field that unambiguously identifies individual parameters.
      Parameter Value is a variable length field that is interpreted
      according to the value of the Parameter Type field.  Unrecognized
      optional parameters MUST be silently ignored.

      This document does not define any optional parameters.

7.3.  UPDATE Message Format

   UPDATE messages are used to transfer Claim/Collision/PrefixManaged
   information between MASC speakers.  The UPDATE message always
   includes the fixed-size MASC header, and one or more attributes as
   described below.  The minimum length of the UPDATE message is 40
   octets (including the message header).

   Each attribute is of the form:

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              Length           |     Type      |   Reserved    |