# Create the update packet:
   my $update = Net::DNS::Update->new($OURDOMAIN);

   #  Add the PTR record:
   $update->push(update => rr_add("$rev 3600 PTR $hst"));

   # Send the update to the zone's primary master.
   my $res = Net::DNS::Resolver->new;
   $res->nameservers("$OURNMSERV");

   my $reply = $res->send($update);