Ken Harrenstien                                           RFC-811
Vic White                                            1 March 1982
Elizabeth Feinler
Network Information Center
SRI International

                        HOSTNAMES SERVER




INTRODUCTION

   The NIC Internet Hostnames Server is an NCP/TCP-based host
   information program and protocol running on the SRI-NIC
   machine.  It is one of a series of ARPANET/Internet name
   services maintained by the Network Information Center (NIC) at
   SRI International on behalf of the Defense Communications
   Agency (DCA).  The function of this particular server is to
   deliver machine-readable name/address information describing
   networks, gateways, hosts, and eventually domains, within the
   internet environment.  As currently implemented, the server
   provides the information outlined in the DoD Internet Host
   Table Specification (RFC 810).

QUERY/RESPONSE FORMAT

   The name server accepts simple text query requests of the form

      <command key> <argument(s)> []

   where square brackets ("[]") indicate an optional field.  The
   command key is a keyword indicating the nature of the request.
   The defined keys are explained below.

   The response, on the other hand, is of the form

      <response key> : <rest of response>

   where <response key> is a keyword indicating the nature of the
   response, and the rest of the response is interpreted in the
   context of the key.

COMMAND/RESPONSE KEYS

   The currently defined keywords are:

      Command Keys:

         HNAME   (find entry with given name)
         HADDR   (find entry with given address)
         ALL     (return entire host table)
         




 

                                                            1 March 1982
RFC 811                                                 Hostnames Server
                                                                        
                                                                        
      Response Keys:

         ERR     (entry not found, nature of error follows)
         NET     (entry found, rest of entry follows)
         GATEWAY (entry found, rest of entry follows)
         HOST    (entry found, rest of entry follows)
         BEGIN   (followed by multiple entries)
         END     (done with BEGIN block of entries)

   More keywords will be added as new needs are recognized.  A
   more detailed description of the allowed requests/responses
   will follow.

PROTOCOL

   To access this server from a program, connect to service host
   (SRI-NIC)

      TCP: port 101 decimal
      NCP: socket 101 decimal for ICP

   send the information query, and await the response.

   Note:  Care should be taken to interpret the nature of the
   reply (e.g, single record or multiple record), so that no
   confusion about the state of the reply results.  An "ALL"
   request will likely return several hundred or more records of
   all types (see RFC 810), whereas "HNAME" or "HADDR" will
   usually return one HOST record, or "BEGIN:", list of host
   records, "END:", if there is more than one match.

QUERY/RESPONSE EXAMPLES

   1. HNAME Query - Given a name, find the entry or entries that
   match
      the name.  For example: