Virtual host and search engines

How do search engines react?

[misciab]

Hi toolman and hi everybody. We are considering the possibility of placing some of the web sites we are promoting in search engines on the same IP.

Does anyone know if it can be dangerous? How do the spiders consider mulpiple submission of the same IP?

Thank you

Miriam

[toolman]

>>>we are promoting in search engines on the same IP

Shouldn't be a problem. I know there's evidence that sometimes spiders may have a problem but I haven't had any problem so far.

I guess it boils down to how critical the mission is....if there is any doubt in your mind...just get separate ip hosting for each site and be done with it.

[seth_wilde]

Back when AV had black Monday many people with virtual hosting got banned for sharing their IP address with a spammer.. but if your actually in control of all the sites using that IP your probably OK...

[Son_House]

Let me see if I understand this. Lets say my site has an ip number of 123.456.789.345
Does virtual hosting mean that x number of sites also have the exact same ip?
Is there away to find out if a site is on a shared ip without calling the place that hosts the site?

[misciab]

Son_House, I've tried to understand the rules for the association IP-domain/s. It's related with directories and subdirectories in the server, I hope technicians help us to clearify the ideas.

Ciao Miriam

[toolman]

In no server admin at all but I'll give a shot.

The IP address in a virtual (name-based) hosting account is like the telephone number to a company.

Once a request is made it will end up at that IP inside of a particular server(the building the company is inside of for our example). From there it's just a matter of the server handling the request according to the map or floorplan of the building the company is in.

JoeBlow.com is down the hall and to the right....SmartyPants.com is three floors up in the corner office. The phone calls all come in to the IP but the server knows the particular floorplan and where to route the individual requests so they get to the right office within the building. Just like a switchboard operator at the front desk..... but the real key word is mapping.

Yes there is some controversy about whether spiders get confused in a name-based environment but I personally haven't had any trouble so far.

[Son_House]

Thank you for the explanation, makes it a lot easier to understand. I never worried about virtual hosting until this past week. Our site is on a shared server but I don't know if it is virtual hosted or not, wanted to get my facts right before I called them. Glad to hear your not having any trouble so far with it.

[ggrot]

toolman. Good analogy, I will extend upon it a bit. When the building is called up, the phone doing the calling needs to ask the building phone system for a specific person. If it doesn't, then the building phone system has no clue who to let you talk to. Often, it then hooks you up with the front desk, or in the server system - the main domain content. Almost all web browsers send this information along the line. You have to go back to something like IE 1.0 to find one that doesn't (although it does happen that people use these browsers from time to time). The trick is whether or not a spider is smart enough to send this information. Usually yes, sometimes no, perhaps even on purpose to see which buildings have lots of people and those that dont.

But that's not really the scary part. The problem would be the data mining capabilities. If for any reason, you want the search engine not to realize that all these people are working for the same company(or all the sites are the same company), you'll need a different phone number/ip address for each. And if you really want to be sure, you don't want the phone numbers to all be just slightly different, or the search engine might realize you just have different numbers going to the same building again. This is what we mean when we talk about class C's. These would analogously be phone numbers with all but the last few digits being identical.

[bobriggs]

I'm curious...

Summary so far:
Each website has a phone number (the IP), so a web browser (or spider for that matter) must do a DNS lookup on the hostname, get the phone number.

If there are multiple people at that phone number (www.domain1.tld and www.domain2.tld), it calls the phone number and asks for domain1 or domain2. (addresses by host name)

Now I just discovered 2 sites (and I'm sure there are many thousands or millions more), that have multiple phone numbers (ip). For instance, I've pinged a certain domain in the last 20 minutes and I've received these:

207.155.252.75
207.155.252.63
and
207.155.253.63

That's what the phone number is, but it's changing. Is this a roaming IP address?

If you type the ip addresses in your web browser, you'll get a cgi program asking for the specific domain name. Then if you type the correct domain, the IE web browser will show:
http:*//207.155.253.63/thecorrectdomain.tld/
as if you had typed
http:*//thecorrectdomain.tld/

If search engines cache the IP addresses of web site domains, that could mean trouble, since it seems that the ip address could be different at any time (unless of course it also sends a domain name request with it)

Any comments on this? How does a DNS server send out roaming ips, if that's what this is?

[toolman]

Just to follow up on this:

I switched a domain from an ip hosted sever to a virtual server. Since it had a Google fresh on it it allowed me to see in real time what was happening.

Googlebot has yet to spider the new virtual host but continues to spider the ip hosted site daily...clearly a delay on Googles part in updating their dns and not a deficiency in the spidering technology.

I continue to update both sites until the transfer takes place in Google world. If it was the other way around (virtual to ip) that could present some difficulties in updating the old virtual host unless my host allowed access by server name...some do not.

[JayC]

Is there away to find out if a site is on a shared ip without calling the place that hosts the site?

There's an easy way, Son_House. Just type the IP into the address box instead of the domain name. That is, using your example, go to [123.456.789.345...] -- if you end up directly at the site in question, it has its own IP address. If you end up either at the host's site or, as bobriggs mentioned above, are prompted to enter a specific domain name, it's a shared IP.

[Son_House]

Thanks JayC, I had know idea it was so easy to do.

Well I tried it and the site is virtual hosted and it probably has been that way since I started with this host. The good news is that the site is in Google and the other se's so I guess it's not a problem.

clearly a delay on Googles part in updating their dns and not a deficiency in the spidering technology.

That makes me worry a bit because the host I'm with said they were going to change the ip's on the shared server's back on Feb 8. Well then they changed there minds and said it would be in a few weeks. I hope it does not happen just as Google is doing the full crawl of the site because they might not pick up the new ip in time and the site would be dropped for a month.