I have three Solaris DNS servers, a master & two secondaries. On the master, There is an A record for one of my secondaries with an IP that is different from that servers physical IP address. There is also a corresponding PTR record for the same server & IP. I am trying to figure out what the purpose of this is.
For bind DNS generally, sometimes servers have multiple interfaces dedicated to different purposes, so a local A and PTR create a local, limited opinion of how to get to it. Of course, the master might share it if asked. It also might be a left over from a temp network setup, too. Normally, all the PTR records for a inet-addr subnet domain are on the same servers synced from their domain master. Some apps are very insistent on a consistent PTR record for a correspondent IP and look up the PTR response name to check the IP, so you need both an A and PTR to use that interface on that app.