Field 5         Operating System

      Field 6         Protocol List

   Fields 4, 5 and 6 are optional.  For a Domain they are not used.

   Fields 3-6, if included, pertain to the first address in Field 2.

   'Blanks' (spaces and tabs) are ignored between data elements or
   fields, but are disallowed within a data element.

   Each entry ends with a colon.

   The entries in the table are grouped by types in the order Domain,
   Net, Gateway, and Host.  Within each type the ordering is
   unspecified.

   Note that although optional nicknames are allowed for hosts, they are
   discouraged, except in the case where host names have been changed





 


RFC 952                                                     October 1985
DOD INTERNET HOST TABLE SPECIFICATION


   and both the new and the old names are maintained for a suitable
   period of time to effect a smooth transition.  Nicknames are not
   permitted for NET names.

GRAMMATICAL HOST TABLE SPECIFICATION

   A. Parsing grammar

       ::=  ":"  ":"  [":" []
         [":" []  [":" [<protocol list>] ]]] ":"
       ::=  *["," ]
       ::=  "."  "."  "." 
       ::= <0 to 255 decimal>
       ::=  |  |  *[","
         ]
         | <official hostname> *["," ]
        ::= 
       ::= 
       ::= 
      <official hostname> ::= 
       ::= 
      <protocol list> ::= <protocol spec> *["," <protocol spec>]
      <protocol spec> ::= <transport name> "/" <service name>
         | <raw protocol name>

   B. Lexical grammar

      <entry-field> ::=  [  <entry-field>]
        ::=  *
       ::= <space-or-tab> []
       ::= NET | GATEWAY | HOST | DOMAIN
       ::= *["."]
        ::= [*[<let-or-digit-or-hyphen>]<let-or-digit>]
       ::= PDP-11/70 | DEC-1080 | C/30 | CDC-6400...etc.
         ::= ITS | MULTICS | TOPS20 | UNIX...etc.
      <transport name> ::= TCP | NCP | UDP | IP...etc.
      <service name> ::= TELNET | FTP | SMTP | MTP...etc.
      <raw protocol name> ::= 
       ::= ";" 
          ::= *[ | ]
        ::= <any printing char (not space or tab)>

   Notes:

      1. Zero or more 'blanks' between separators " , : " are allowed.
      'Blanks' are spaces and tabs.




 


RFC 952                                                     October 1985
DOD INTERNET HOST TABLE SPECIFICATION


      2. Continuation lines are lines that begin with at least one
      blank.  They may be used anywhere 'blanks' are legal to split an
      entry across lines.

BIBLIOGRAPHY

   1. Feinler, E., Harrenstien, K., Su, Z. and White, V., "Official DoD
      Internet Host Table Specification", RFC-810, Network Information
      Center, SRI International, March 1982.

   2. Harrenstien, K., Stahl, M., and Feinler, E., "Hostname Server",