To enable a subdomain type of installation in WordPress MU, you’ll need a wildcard entry in the DNS. The following instructions applies only to Dreamhost users, but they can be easily adapted to other CPanels or other host providers.
- Login to the Dreamhost’s Panel
- Click on the Manage Domains
- Find yourdomain.com and click the DNS link
- Add a custom DNS to yourdomain.com. See entry below
- Click the Add Record Now submit button
Custom DNS Entry
Comment: wildcard dns script
If your provider does not provide you with the facility to add DNS records, please contact the support team telling them you need a wildcard entry in the DNS for a particular domain. They are usually happy to enter it for you. Please note some providers don’t allow wildcard entries, then you are better off using a subdirectory structure or moving to another host provider that supports it.
You literally do not need to add subdomains to yourdomain.com when installing WordPress MU. I made that mistake. The DNS wildcard and Apache’s mod_rewrite module should do the trick for you. As long as you have those two requirements, the subdomain type of install of WordPress MU will work.