RE: Reverse Lookup using IP Address in EPP?

["Hollenbeck, Scott" <shollenbeck@verisign.com>]

> -----Original Message-----
> From: Liu, Hong [mailto:Hong.Liu@neustar.biz]
> Sent: Tuesday, February 26, 2002 12:43 PM
> To: ietf-provreg@cafax.se
> Subject: Reverse Lookup using IP Address in EPP?
> 
> 
> 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.

FWIW our requirements draft specifically says (see 3.4.2-[3]) that an IP
address can be associated with multiple registered hosts.  EPP doesn't
include any restrictions in this regard.

> 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.

We talked about this some time ago.  My argument against it at the time was
that it involves doing object lookup using an object attribute as a key,
which is out of place in a provisioning protocol.  As far as I know most
operators make it possible to use whois to find hosts by IP address.

-Scott-