Reverse Lookup using IP Address in EPP?

["Liu, Hong" <Hong.Liu@neustar.biz>]

The current registry practice requires that an unique IP address be assigned
to each name server in the same name space. That is, if an IP address is
already used by an NS, it cannot be used for another NS. It is very
difficult to find out which host has used the IP address, without looking at
the zone file, or calling customer support. Even zone files may not contain
the host if it is an orphan NS in the registry. This is the out-of-band
method.

One possible way to resolve this issue is to provide reverse lookup based on
an IP address via the registrar-registry interface, i.e., in-band method.
Based on the returned host name, the requesting party knows whether that
host is still in use as an NS or not. In the case of an orphan NS, the
requesting party can tell the registry to remove the A RR for the host.

However, this requires that the current EPP protocol be extended to include
such capability in the host mapping part. I would like to know how the WG
feels about this issue. I would also like to hear other alternatives for
solving this problem.

Cheers,

--Hong