Important: This was written in 2012, when you needed to use a plugin for domain mapping. With version 5.something of WordPress, and with version 6+, domain mapping is built into the WordPress core.
If you were using the obsolete plugin for domain mapping, you should document the exact domain names you were mapping to, for each site. Then, network disable it and then delete it.
In new versions of WordPress, you simply put the domain name you want into My Sites, Network Admin, Sites, then hover over the site you want, click Edit, in the Info tab edit the “Site Address (URL)” field. Use the full URL, including https://
You still have to set the DNS so the domain name points to your WordPress Multi-Site installation.
With WordPress version 3+ or 4+ in Multi-Site Mode, and the Domain Mapping Plugin, you can map domain names to any of your blogs. I’ll walk you through the steps to install the plugin (you have to move a few files and edit some configuration settings). Then I’ll show how to specify the mappings you want. (There are several blogs with partial instructions, that didn’t explain the configuration settings and didn’t give examples of how to specify the mappings — but you won’t have to figure it out because I did!)
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