As landed, the FQDN maps to the "primary" IP, and everything else gets IFACE.FQDN -- with possible multi-address and/or multi-PTR RRs in the RRset, which makes sense.
As landed, the FQDN maps to the "primary" IP, and everything else gets IFACE.FQDN -- with possible multi-address and/or multi-PTR RRs in the RRset, which makes sense.