Len Conrad wrote:
It should not be mandatory for a PTR record to match "the" A record.
it should be mandatory that the PTR and A match
But any reliable publisher of PTR records should publish at least an
A record that matches it
contradicting your above
, even if it's not "the" A record.
WTF??
The owner of the address block needs to publish only one PTR record --
it needs to resolve to only one name (obviously), which should be in a
domain also owned by the owner of the address block.
Client domains may, of course, publish A records. There is, of course,
no way of guaranteeing there is a PTR record that will match that name
-- only that some PTR record exists.