Hosting multiple sites with one IP address
 

Would it be possible to host multiple websites under one IP address?

If so, how is this normally done?

NameVirtualHost & in Apache, unless you need to do thousands, in which case look for 'mass vhost' on http://httpd.apache.org/ Mass VHost can also be done using mod_rewrite.

Tux does it automatically, but requires your docroot to be set up in a specific way

AOLServer requires multiple ns_sock statements and a funny frontend.tcl configuration

Caudium requires the Virtual Host Matcher module and uses regexp's and a master domain to do the backend redirection.

Boa requires a VirtualHost Directive and a specific directory layout

thttpd requires vhost directives in the command line upon invocation

zeus does it through their web admin system, and doesn't require a restart

..... :)

I've got several hundred domains spread over a whole range of hosting companies. You just open virtual account with them and load the domains. Hosts like www.varzi.net will give you a control panel and you can just add the domains yourself. Other hosts such as www.cyberwurx.com require you to submit a ticket to add a domain, but as they usually respond in about 5 minutes, it isn't a problem.

One disadvantage of using a single IP is the the search engines will lump all your domains together, and they may not count your interlinking for SE promotion.

I don't think that's necessarily true (it may be but I don't think it is) since ARIN announced a clampdown on the number of new ips that would be made available.

I have a box with Rackshack (or whatever it's called now) and I only have two IPs for my nameservers - all my domains are virtual name based. I believe the only extra IPs I could get would be for SSL.

I'd be interested in other peoples opinions on this, as I'm not too hot on SEO.
There is talk suggesting that the reason Google became a domain registrar is to give them access to the registration details, so I guess they are trying to check on incestuous linking.

I've heard the same thing you stated above about interlinking domains on a single IP. I've only heard it applied to Google, but what they do, the herd will surely follow.

Heh, incestuous linking, that's a new one I've heard.

But what you're saying is right, Google has stated over and over that they do not plan on becoming a registrar. So one can only assume that they will be using it for the other obvious reason.

The controversial Matt Cutts has stated that he prefers to have domains located on different c-class IPs.

Sure you can! Any shared hosting account should allow it. The number of domains you can add varies from one hosting company to the other.

I will get another IP only for SSL.

Technically there's no problem. it's up to your hosting company. My hobby is/was collecting niche domains, and I've got more than one hosting account with 80 or so domains on the same IP. Google doesn't seem to like me though, and I've never really understood this. If I register a domain for gay gloryholes, and one for gay dogging, and I link to them both from a general gay site, I don't see what the problem is. I also like to collect sub-niche and cross-over niche domains, and I would have thought that that would have been great for google. One example is a recent site for galleries of girls peeing while they are tied up. :)

i have heard the same thing.

Don't host adult and non-adult domains together under the same IP. Some filtering software will stop the non-adult surfers from seeing their sites. ... Been there done that!!! ... art