Who is sharing a web server?

February 9, 2006 4:54 PM

Is there an easy way to find out which domain names are using the same shared hosting server? Ideally, there is a web site or free download (OS X preferred) that can tell me which domain names resolve to a particular ip address. I've fooled around with most of the functions on samspade.org and haven't seen one that does this.
posted by i love cheese to computers & internet (11 comments total)

I could point my own domain anywhere, regardless of where I host my files. Methinks a solution would require that you have access to root DNS servers.
posted by odinsdream at 4:56 PM on February 9, 2006

DNS does not allow you to find all hostnames for an IP address, only the other way around. You *do* have access to the root servers (everyone does, really), but that isn't the problem. It just doesn't work like that.

Unfortunately, the Yahoo Site Explorer doesn't index this way, but it's still a very cool tool for related searches.
posted by kcm at 5:13 PM on February 9, 2006

The only place all that data would come together is in the webserver's configuration files on that particular server.

That said, Netcraft aggregates per-netblock information for the sites it has data on. For instance, here are the sites in the netblock that www.metafilter.com is in, but that starts off knowing one site in the netblock, and it's a netblock, not just one server, and it's only the servers Netcraft has been asked about in the past, not a complete list.
posted by mendel at 5:16 PM on February 9, 2006

the folks over at whois.sc have a reverse ip lookup tool.
posted by a. at 5:22 PM on February 9, 2006

You'd have to have access to the root servers in a way that allowed you to say: "Give me all the domains that point to X.X.X.X." which..you don't, as far as I know.
posted by odinsdream at 5:22 PM on February 9, 2006

go to dnsstuff.com, look up a domain using the 'domain info' box. click where it says 'hosts X domains'! you'll need to get a free login to do this.
posted by soma lkzx at 6:23 PM on February 9, 2006

whois.sc (also accessed from dnsstuff.com) only lists the first 3 domains per ip address with a free login, unfortunately. they want $$ before they'll show you any more.
posted by cgg at 7:23 PM on February 9, 2006

doh! sorry, i wasnt aware of the need of $ for the whois.sc tool. i'm certain it was free a while ago though.
posted by a. at 7:30 PM on February 9, 2006

The UNIX 'nslookup' utility will do what whois.sc will do, I'm guessing.

You'll only get the domains that have reverse DNS set up. For domains without rdns, they can point to any IP, even if the IP doesn't know about it. Most major websites and mailservers will have RDNS, though.

Sample session:

dante:john {118} nslookup bbc.co.uk
Server: 192.168.0.1
Address: 192.168.0.1#53

Non-authoritative answer:
Name: bbc.co.uk
Address: 212.58.224.131

dante:john {119} nslookup 212.58.224.131
Server: 192.168.0.1
Address: 192.168.0.1#53

Non-authoritative answer:
131.224.58.212.in-addr.arpa name = rdirwww-vip.thdo.bbc.co.uk.

Authoritative answers can be found from:

posted by devilsbrigade at 7:53 PM on February 9, 2006

The UNIX 'nslookup' utility will do what whois.sc will do, I'm guessing.

No, sorry, that's not even remotely the same, not by a long shot.

Using virtual servers, you can host a virtually unlimited number of domains on a single IP address. This is extremely common. Reverse DNS only allows for a single name to map to an IP address, and usually it has nothing whatsoever to do with the actual domains that are hosted. So it's impossible to get this information from a simple DNS query, because it only exists in the Apache configuration files and the DNS servers of all the hosted domains.

What whois.sc has done is download the master zone file for .com, .net, .org (and some others) and then go through every single domain, query every listed nameserver for the A record of each domain, and then note which ones return the same A record. That is the only way of getting this information and it requires an extraordinary amount of work.

webhosting.info also has a similar service.
posted by Rhomboid at 8:57 PM on February 9, 2006

webhosting.info does it for free, but whois.sc has *much* nicer results.. it's $149/yr, though. :(
posted by drstein at 9:33 PM on February 9, 2006