RFC 1931 (rfc1931) - Page 2 of 11

Dynamic RARP Extensions for Automatic Network Address Acquisition

RFC 1931                      Dynamic RARP                    April 1996


   which extended BOOTP.

   The "hands-off" installation of all kinds of systems (including
   diskless workstations, and servers) was required, as supported by
   LocalTalk networks [8].  However, Internet administrative models are
   not set up to allow that: there is no way to set up a completely
   functional IP network by just plugging machines into a cable and
   powering them up.  That procedure doesn't have a way to input the
   network number (and class) that must be used, or to bootstrap the
   host naming system.  An approach based on administered servers was
   needed for IP-based "Intranet" systems, even though that
   unfortunately called for networks to be initially set up by
   knowledgeable staff before any "hands-off" installations could be
   performed.

1.2  System Overview

   DRARP was used by systems in the first phase of joining a network, to
   acquire a network address without personal intervention by a network
   administrator.  Once a system was given a network address, it would
   perform whatever network operations it desired, subject to a site's
   access control policies.  During system installation, those network
   operations involved a (re)configuration protocol ("Plug'n'Play", or
   PNP).  Diskless sytems used TFTP to download code which could speak
   the PNP protocol.

   The PNP protocol would register the names of newly installed hosts in
   the naming service, using the address which was acquired using DRARP.
   These names could be chosen by users installing the system, but could
   also be assigned automatically.  Diskless systems used the PNP
   protocol to assign booting resources (e.g. filesystem space) on
   servers.  All systems were assigned public and private keys, also
   initial (quasi-secret) "root" passwords, so that they could use what
   was then the strongest available ONC RPC authentication system.

   Servers for DRARP and for the configuration protocol (as well as
   other administrative tools) needed to consult an authoritative
   database of which Internet addresses which were allocated to which
   hosts (as identified by hardware addresses).  This "address
   authority" role was implemented using a name service (NIS) and an
   RPC-based centralized IP address allocation protocol ("IPalloc").
   Address allocation could be performed only by authorized users,
   including network administrators and DRARP servers.

   Most systems used DRARP and PNP each time they started, to
   automatically reconfigure applicable system and network policies.
   For example, network addresses and numbers were changed using these
   protocols; host names changed less often.  The naming service (NIS)



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