When you create a new reverse zone, you can enter a range using the x-y syntax. that's it. From now on, Linuxconf will update the the zone if the IP number fits in that range. The zone will be named
for a a.b.c network.
I put a check-box for each. I also reworked the dialog to place options together under a new tab called "SMTP features".
You can turn off this automatic update right in the NIS configuration dialog.