Re: Reverse Lookup using IP Address in EPP?

[Patrick <patrick@gandi.net>]

On Tue, Feb 26, 2002 at 11:42:44AM -0600, Liu, Hong took time to write:
> 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

It seems not to be true anymore for Verisign.

> 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.

There is no need to. whois (Registry) is sufficient, as long as it
contains data about nameservers and that it can be queried by
nameserver's name or by IP.

This is the current case of whois.Verisign-grs.net

> 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.

I would suggest something simpler if you really want the
restriction of 1 IP :
when you create a nameserer and that fails because the IP is already
used, put the nameserver already registered with the given IP in the
error message of the creation.

Patrick.