Multisite – Different i.p for each sub site

Off the top of my head, I want to say yes, but the idea in my head would involve multiple web servers, one on each IP, with semi-unique configuration to stay independent of each other.

With the availability of resources these days to host a site, why can’t each site be on its own host? I’m curious as to the need for using unique IP addresses?

Cheers for the reply. Yeah i’m thinking maybe the best option is to host each site on it’s own host. The reason… a few years back we wanted to do it for SSL reasons and gave up on the idea.

This time round our client (who we manage the site for) has been instructed by his SEO guy that it would be better if each site lived on it’s own i.p with each i.p having a different C Class. For SEO reasons.

WordPress works off of hostnames/domains; so you shouldnt need to do any extra configuration in WP to handle individual IP addresses. Handling IP address is at the DNS or hosting level. It is simple to give hostnames a specific IP address. It is simple to have one server configured with all those IP addresses/hostnames. The more difficult situation would be if you wanted to do ssl. That can be solved fairly easy too.

FYI, we (USC) have a multisite system setup that hosts over 300 sites. 99% of our sites use the same IP address though some sites have their own IP address. We handle this at the load balancer layer.

The only time you’d run into SEO trouble with not having unique IPs is if one of them was blacklisted. Something sounds fishy about that.

Thanks jkhongusc i’ll look into this more. Cheersfor pointing me in the DNS direction.

No nothing fishy Johnathan. The server i.p is totally fine and not blacklisted so there’s no penalties in terms of SEO for these sites. Our clients just been instructed by their SEO guy that if each sites got it’s own unique C Class i.p the sites will rank better. Which means giving each sub site it’s own i.p each with a unique C Class part.

It’s a little over my head that part (in temrs of SEO) but that’s what they’ve been advised to do.

Thanks for the replies.

More details regarding SSL. For our situation, all of our WP sites are subdomains: site1.usc.edu, site2.usc.edu, site3.usc.edu. I didnt have to change any web server settings to accomodate separate IP address… all sites use the same wildcard certificate (*.usc.edu). We do have non-WP sites that use different domains: https://www.domain1.com, https://www.domain2.com. In this case you need separate web server configurations for each site; in addition you can either use separate certificates or a wildcard domain cert (expensive).

jkhongusc… Quick question. We’re using a linex server WHM /cPanel. When you did specific i.p’s for hostnames did you set the specific hostname i.p in /etc/hosts? or can it be done in WHM / cPanel somewhere?

Thanks

Just so you know: NO ONE will really support their plugins and themes if you do this. There’s no point.

The reason… a few years back we wanted to do it for SSL reasons and gave up on the idea.

You don’t need to, not even for SSL.

https://wiki.apache.org/httpd/NameBasedSSLVHostsWithSNI