CNAME - identifies the canonical name of an alias

      This memo uses the following classes in its examples:

         IN - the ARPA Internet system

         CS - the CSNET system

      The first type of resource record holds a host name to host
      address binding.  Its fields are:

  +--------+--------+--------+--------------//----------------------+
  | |   A    | | <class specific address>information  |
  +--------+--------+--------+--------------//----------------------+






 

RFC 882                                                    November 1983
                                  Domain Names - Concepts and Facilities


      The content of the class specific information varies according to
      the value in the CLASS field; for the ARPA Internet, it is the 32
      bit ARPA Internet address of the host, for the CSNET it might be
      the phone number of the host.  For example, F.ISI.ARPA might have
      two A records of the form:

       +----------+--------+--------+----------------------------+
       |F.ISI.ARPA|   A    |   IN   |          10.2.0.52         |
       +----------+--------+--------+----------------------------+
                                  and
       +----------+--------+--------+----------------------------+
       |F.ISI.ARPA|   A    |   CS   |         213-822-2112       |
       +----------+--------+--------+----------------------------+

      Note that the data formats for the A type are class dependent, and
      the Internet address and phone number formats shown above are for
      purposes of illustration only.  The actual data formats are
      specified in [14].  For example, CS class data for type A records
      might actually be a list of Internet addresses, phone numbers and
      TELENET addresses.

      The mail forwarder (MF) and mail delivery (MD) records have the
      following format:

        +--------+--------+--------+----------------------------+
        | | MD/MF  | |       <domain name>        |
        +--------+--------+--------+----------------------------+

      The <domain name> field is a domain name of the host that will
      handle mail; note that this domain name may be completely
      different from the domain name which names the resource record.
      For example, F.ISI.ARPA might have two records of the form:

       +----------+--------+--------+----------------------------+
       |F.ISI.ARPA|  MD    |   IN   |         F.ISI.ARPA         |
       +----------+--------+--------+----------------------------+
                                  and
       +----------+--------+--------+----------------------------+
       |F.ISI.ARPA|  MF    |   IN   |         B.ISI.ARPA         |
       +----------+--------+--------+----------------------------+

      These records mean that mail for F.ISI.ARPA can either be
      delivered to the host F.ISI.ARPA or forwarded to B.ISI.ARPA, which
      will accept responsibility for its eventual delivery.  In
      principle, an additional name lookup is required to map the domain
      name of the host to the appropriate address, in practice this
      information is usually returned in the response to the mail query.

      The SOA and NS types of resource records are used to define limits



 

RFC 882                                                    November 1983
                                  Domain Names - Concepts and Facilities


      of authority.  The domain name given by the owner field of a SOA
      record is the start of a zone; the domain name given by the owner
      field of a NS record identifies a point in the name space where
      authority has been delegated, and hence marks the zone boundary.
      Except in the case where a name server delegates authority to
      itself, the SOA identifies the top limit of authority, and NS
      records define the first name outside of a zone.  These resource
      records have a standard format for all of the name space:

      +----------+--------+--------+-----------------------------+
      |   |   SOA  | |       <domain name, etc>    |
      +----------+--------+--------+-----------------------------+
                                    
      +----------+--------+--------+-----------------------------+
      |   |   NS   | |       <domain name>         |