On Fri, 18 Mar 2011, Michael B Allen wrote: > True. You cannot have multiple PTR records for an IP. I did not mean > to suggest that you could. Not saying you are wrong here, but have you an RFC reference to this effect? We previously held this belief from our prior practice, but cannot find a clear prohibition of such. As such our DNS zonefile management code does not enforce such a limitation presently Considering the issue from the other side, there is nothing that requires simplicity if implementation of a client that says it can accept only a single PTR, rather than an array of replies and then walking the reverses -- Russ herrold