firewall machine

firewall machine n.  A dedicated gateway machine with
   special security precautions on it, used to service outside network
   connections and dial-in lines.  The idea is to protect a cluster of
   more loosely administered machines hidden behind it from
   {cracker}s.  The typical firewall is an inexpensive micro-based
   UNIX box kept clean of critical data, with a bunch of modems and
   public network ports on it but just one carefully watched
   connection back to the rest of the cluster.  The special
   precautions may include threat monitoring, callback, and even a
   complete {iron box} keyable to particular incoming IDs or
   activity patterns.  Syn. {flytrap}, {Venus flytrap}.