This test checks whether zones configured with "type mirror;" behave as expected. ns1 is an authoritative-only server. It only serves the root zone, which is mirrored by ns3. ns2 is an authoritative-only server. It serves a number of zones, some of which are delegated to it by ns1 and used in recursive resolution tests aimed at ns3 while others are only served so that ns3 has a primary server to mirror zones from during various tests of the mirror zone implementation. ns3 is a recursive resolver. It has a number of mirror zones configured. This is the only server whose behavior is being examined by this system test.