ddawkins

I figured it out . . .

The following information is for a Multisite Subdomain install on your own IIS server, NOT for a hosted install.

If you don’t add a binding for the subdomain in IIS, IIS doesn’t send it to WordPress, it just gives you a 404 Error.

I had to fix the IIS server bindings to include the subdomain. It turns out that to get to your Subdomain Site on an IIS WordPress Multisite installation, you have to:

1) Install WordPress correctly (this is done on/from your IIS server)

2) Upgrade to Multisite correctly (this is done by editing a few WordPress files that were installed on your IIS server). See the note below about trying to upgrade to Multisite when you installed WordPress with Microsoft Web Platform Installer or your WordPress install ended up in its own folder instead of the IIS root directory, or your don’t get the Subdomain option when you try to do Network Setup.

3) Configure DNS correctly (this is usually done through your domain registrar, or whomever controls the DNS zone file for your domain). For instance, if GoDaddy is your registrar, then you would log into GoDaddy and open their DNS management tool for your domain to add a wildcard CNAME entry that points to your WordPress server. It could look like, * points to domain.com, where domain.com points to your WordPress server. Or you could add a discrete entry for each new subdomain like subdomain points to domain.com. It might take DNS a while to propagate (minutes or several hours). Once it does, you shold be able to ping subdomain.domain.com and get a response. If you do, then the DNS should be OK.

4) Set up IIS to know what to do with a request for the subdomain. You have to go into the IIS control panel, select your site, the go to the Bindings option (in the upper left of the screen) to add a binding for subdomain.domain.com. Now when DNS forwards your request to the IIS server, it will know to send it to the WordPress site and WordPress should then figure out how to send the request to the correct subdomain pages.

That should do it if you have an internal IIS install of WordPress Multisite using Subdomains.

NOTE:
The Subdomain option will not show up if you don’t have WordPress installed in the root directory of the IIS server. On a hosted system, it is usually in a directory like /public_html/. On IIS, it should be in the inetpub\wwwroot folder. The path to it, from the Web server’s point of view, is simply /, because wwwroot is the root folder for IIS.

If you used Microsoft Web Platform Installer to install WordPress onto your Windows server, it puts everything into inetpub\wwwroot\wordpress, and that will not give you the option to use Subdomains when you upgrade to Multisite. To get the Subdomain option when you click Network Setup, you have to move all the files from the wordpress folder up one level into the wwwroot folder. Now, when you click on Network Setup, you should see the Subdomain option.