Re: [SLUG] Sites on IP

From: Richard Morgan (
Date: Mon Apr 10 2006 - 12:27:39 EDT

Quoting Paul M Foster <>:

> Richard Morgan wrote:
> > Quoting Paul M Foster <>:
> >
> >> Two questions:
> >>
> >> 1. Since many sites can share the same IP, is there any way to tell
> >> all the websites which share an IP?
> >>
> >> 2. Assuming you have a "reseller account" with a hosting company,
> >> where they give you two IPs for your sites, is it possible or probable
> >> that they have also given someone else those same IPs? Is this common
> >> practice or not?
> >>
>> Yes, it's very common to "oversell" IP's since they are such a
>> precious thing,
>> nowadays. You should be able to find all of the hosts on a given IP with
>> reverse DNS and some commercial web hosting services, like Also,
>> Netcraft may give you that information, too.
> Reverse DNS won't do it. I tried.
> Here's my understanding of how this works. Correct me if I'm wrong.
> Let's say server alfa is the authoritative DNS server for 50 domains.
> Its BIND tables show all the translations from sitename to IP. But a
> DNS query supplies a sitename and asks for an IP. Alfa is glad to
> oblige, but that query doesn't say anything about what *other* sites
> share that IP. Now, I don't know much about how DNS works. I don't
> know how those DNS tables are populated. Are there CNAME entries, A
> entries, PTR entries for each site in the tables? But how would you
> get a flush of those tables? Trying reverse DNS didn't do it. I'll
> supply the IP offlist, if you like (I don't want that IP up on the
> internet forever for people to hack).
> translates to Their reverse DNS requires
> membership.

Sorry that I can't help you more - I use for that purpose. You could
also try

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