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               In large networks of Digital Equipment Corporation computers
          using  DEC's DECnet networking software, it is often desirable to
          have a method  of  automatically  reconfiguring  the  network  to
          adjust to changing conditions.

               In large DECnets, change is constant;  new nodes  enter  the
          network,  old nodes are removed, partitioned subnets are started,
          and  node  names  are  changed.   This  information  is   usually
          distributed   to   the  various  nodes  by  transferring  a  file
          containing node assignment information for all  the  nodes;   but
          this  is slow, error-prone, wasteful of expensive programmer time
          and effective only if the network is relatively  small.   When  a
          network becomes much larger than 50 machines, the effort required
          to update  network  configuration  information  on  all  machines
          simultaneously becomes prohibitive.

               It is possible to avoid this problem by assigning a  central
          node as a record-keeper for the entire network.  If this is done,
          when a node enters the network all it needs to do is  interrogate
          the  record-keeping node about the current network configuration.
          This has the advantages of  updating  each  node's  configuration
          information  whenever  the  node is restarted and of centralizing
          the network configuration information.

               INTERR  is  a  program  which   interrogates   the   Network
          Management  Listener  /  Network Information and Control Executor
          (NICE/NML) on a central node to  obtain  node  numbers  and  node
          names  for  the  current  network  configuration.   When  it  has
          obtained this information, it spawns  NCP  SET  commands  to  the
          local  host  to  set  this  information  locally.   An additional
          advantage of INTERR is that, for networks which  are  partitioned
          into  subnets,  it is possible to interrogate a node in the local
          subnet for information rather than a globally  known  node  which
          would not know about the subnetwork nodes.

               To build INTERR, invoke  the  build  command  file,  INTGEN.
          INTGEN  should  normally  build the task (on an M V4/M-Plus V2 or
          later system) without significant intervention.

               More documentation is available in INTERR.RNO.   Direct  all
          other inquiries, comments and suggestions - IN WRITING ONLY - to:

                           Bruce R. Mitchell
                           Machine Intelligence and Industrial Magic
                           PO Box 601
                           Hudson, Wisconsin
                           54016

               Attempted phone calls and in-person visits will be  politely
          rejected.

