 the feature in case the client's reverse DNS
        entry is not set up or yields some undesirable host name.
        It is done primarily for efficiency: this way, a connection attempt
        requires at most two resolver lookups, one reverse and one forward.
        If there is a resolver problem with some address, it becomes only
        that client's problem.  A hypothetical alternative
        implementation that only did forward lookups would have to
        resolve every host name mentioned in
   