draft-park-ipv6-extensions-dns-pnp-00.txt

非常好的dns解析软件

        - 6DNAC Server must recognize and process the following NDP
          extensions
      
              - If the 6DNAC Server is a router on the link, then it
                must advertise DNS Zone Suffix option in RA messages
                for hosts to generate their domain name (FQDN).

              - FQDN option in NS messages for detecting new DNS
                information for of nodes on the link for which it
                must update the AAAA RR and PTR RR in DNS Server.

              - FQDN option in NA messages for notifying duplicate
                domain name with unspecified target address.
  
        - 6DNAC server must update the DNS Server (both AAAA RR and
          PTR RR) dynamically using DDNS UPDATE [2136].
  
        - 6DNAC server must cache this (newly detected) FQDN, Link
          Layer Address, and IPv6 Address information, so that it can
          decide whether it really needs to update DNS Server or not,
          to avoid redundant updates. This information will also be
          used for notifying the duplicate domain name.
  
  
  6. 6DNAC Messages and Option Formats
  
  In order to achieve the plug and play DNS, 6DNAC proposes new 
  extensions to the NDP [2461]. This section specifies the new
  additions to NDP messages and formats of new options.
  
  
  6.1. Router Advertisement (RA) Message Format
  
  Routers send out Router Advertisement (RA) message periodically, or
  in response to a Router Solicitation. 6DNAC does not modify the format
  of the RA message, but proposes new option (DNS Zone Suffix Information)
  to be carried in RA messages.








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INTERNET-DRAFT     IPv6 Extensions for DNS Plug and Play      April 2003
  
      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      |     Code      |          Checksum             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Cur Hop Limit |M|O|  Reserved |       Router Lifetime         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         Reachable Time                        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          Retrans Timer                        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Options ...                                                 |
     /                                                               /
     |                  DNS Zone Suffix Information                  |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  
  
                          <Figure: 1 RA message>
  
  
  
  6.2. Neighbor Solicitation (NS) Message Format 
  
  6DNAC does not modify the format of the Neighbor Solicitation (NS)
  message, but proposes new option (FQDN Option) to be carried in NS
  messages. When a node is going for DAD, the node must include FQDN
  option in NS message to participate in plug and play DNS. If the
  node is going for Explicit Detection of Duplicate Domain Name, the
  node must use FQDN option in NS message and unspecified address in
  the target address field.
  
  
      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      |     Code      |          Checksum             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Reserved                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     +                                                               +
     |                                                               |
     +                       Target Address                          +
     |                                                               |
     +                                                               +
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Options ...                                                 |
     /                                                               /
     |                         Domain Name                           |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  
  
                         <Figure: 2 NS message>
  
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  6.3. Neighbor Advertisement (NA) Message Format 
  
  6DNAC does not modify the format of the Neighbor Advertisement (NA)
  message, but proposes new option (FQDN Option) to be carried in NA
  messages. 6DNAC Server sends NA message with FQDN option to 6DNAC
  Client that is performing duplicate domain name detection in case
  the domain name found to be duplicate.

      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      |     Code      |          Checksum             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |R|S|O|                     Reserved                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     +                                                               +
     |                                                               |
     +                       Target Address                          +
     |                                                               |
     +                                                               +
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Options ...                                                 |
     /                                                               /
     |                         FQDN Option                           |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  
  
                          <Figure: 3 NA message> 
  
  
  6.4 Option Formats
  
  6.4.1. DNS Zone Suffix Information Option Format
  
  IPv6 nodes require DNS Zone Suffix for constructing their FQDN.
  6DNAC introduces new option for routers to advertise the DNS Zone
  Suffix Information for IPv6 nodes on the link. The suffix information
  should be configured into routers manually.

      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     |          Reserved             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          Valid Lifetime                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     /                       DNS Zone Suffix                         /
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  
  
                   <Figure: 4 DNS Zone Suffix Information>

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  Type              [TBD]
  
  Length            8-bit unsigned integer. The length of the option
                    (including the type and length fields) in units of
                    8 octets.
  
  Reserved          This field is unused. It must be initialized to zero
                    by the sender and must be ignored by the receiver.
  
  Valid Life Time   32-bit signed integer.  The maximum time, in 
                    seconds, over which this suffix is valid. Nodes 
                    should treat this as the life time for their domain
                    name. Nodes should contact the source of this
                    information before expiry of this time interval.
                    A value of all one bits (0xFFFFFFFF) represents
                    infinity.
  
  DNS Zone Suffix   The suffix part of the FQDN. The data in the DNS 
                    Zone Suffix field should be encoded according to 
                    DNS encoding rules specified in [1035].
  
  
  
  6.4.2. Domain Name (FQDN) Option Format
  
  
      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     |          Reserved             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          Valid Lifetime                       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     +                                                               +
     |                                                               |
     +                       FQDN Target Address                     +
     |                                                               |
     +                                                               +
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     /                         Domain Name                           /
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  
  
                      <Figure: 5 FQDN Information>
  
  Type                 [TBD]
  
  Length               8-bit unsigned integer. The length of the option
                       (including the type and length fields) in units 
                       of 8 octets.  It must be greater than 3.
                       
                       

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  Reserved             This field is unused. It must be initialized to
                       zero by the sender and must be ignored by the
                       receiver.
  
  Valid Life Time      32-bit signed integer.  The maximum time, in 
                       seconds, over which this domain name is valid
                       6DNAC should deregister this domain name at
                       the expiry of this interval. 6DNAC clients
                       should send updates by the expiry of this 
                       interval. A value of all one bits (0xFFFFFFFF)
                       represents infinity.

  FQDN Target Address  The Address for which the FQDN maps to.  It 
                       should be same as Target Address field of the 
                       NS message in case of DAD & duplicate FQDN are
                       running in parallel.

  Domain Name          The domain name (FQDN) of the node. The data in
                       the domain name should be encoded according to
                       DNS encoding rules specified in [1035].
  
  
  6.4.3. Router Alert Option for 6DNAC

  Router Alert Option for 6DNAC is new option within the IPv6 Hop-by-Hop
  Header for using in NDP messages.  The presence of this option in NS
  message informs the router that this NS message is carrying Domain
  Name information and must be processed by the 6DNAC Server on the router.
  6DNAC Clients can use this option for sending DAD packets instead
  of addressing the DAD packets to the all-nodes multicast address
  when 6DNAC Server is implemented on router.
 
  The Router Alert option has the following format:

  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |0 0 0|0 0 1 0 1|0 0 0 0 0 0 1 0|        Value (2 octets)       |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                     Length = 2

  Values are registered and maintained by the IANA. For 6DNAC, the 
  value has to be assigned by IANA.

  Further information about this option can be obtained from 
  IPv6 Router Alert Option [2711].


  7. 6DNAC Operation
  
  6DNAC provides mechanisms for automatic generation of domain name
  and registering it with the DNS Server for IPv6 nodes. 6DNAC consists
  of two components: 6DNAC Client and 6DNAC Server. All nodes that want
  to participate in plug and play DNS are required to implement 6DNAC
  Client functionality, and one of the IPv6 nodes is required to 
  implement 6DNAC Server functionality. The IPv6 node that implements 
  the 6DNAC Server functionality must know the location of the DNS 
  Server and must be a trusted node to send DDNS UPDATE [2136] messages.

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  7.1. 6DNAC Network Topology
  
  This section identifies the possible locations for the 6DNAC Server.
  Note that, all nodes are required to implement 6DNAC Client 
  functionality for constructing the domain name from the DNS Zone 
  Suffix Information advertised by the router.  Figure 6 illustrates 
  IPv6 host (H4) implementing 6DNAC Server functionality. In this case 
  H4 can serve only one link (that it belongs to) for automatic 
  registration of domain name. H4 must observe the DAD packets on the 
  link to detect the DNS information, this requires all nodes on the 
  link must belong to same solicited node multicast address. In general,
  this may not be the case. So the node that is going for DAD must use
  all nodes multicast address for DAD packets, so that the 6DNAC Server
  (H4) can observe the DAD packets, detects IPv6 address and 
  corresponding domain name, checks if this domain name is duplicate 
  and finally registers the domain name with the DNS Server.
 
  
                          6DNAC Server
      +---+                   +---+                     +----------+
      | H1|                   | H4|<--- DDNS UPDATE --->|DNS Server|
      +-+-+                   +-+-+                     +----+-----+
        |                       |           +----+       +---/
        |                       |           |    |      /
     ---+-----+-----------+-----+-----------+ R1 +-----+
              |           |                 |    |
              |           |                 +----+