# What Should Your FQDN Be? Say I own `example.com` and I want to use Gluu Server for authentication. Nothing special, I want to use Gluu to allow user to log in and log out of the site. If it is a pre-existing site would I use: ``` "GLUU_FQDN": "example.com", "IS_GLUU_FQDN_REGISTERED": "Y", ``` -- and if it's to be developed but still owned by me -- ``` "GLUU_FQDN": "example.com", "IS_GLUU_FQDN_REGISTERED": "N", ``` Now, what if I wanted to use Gluu Server as some sort of standalone authentication service. I want it to run authentication for `admin.example.com`, `app.example.com`, and `example.com`. Would I do something like: ``` "GLUU_FQDN": "auth.example.com", "IS_GLUU_FQDN_REGISTERED": "N", ``` -- or would I need some pre-existing app on `auth.example.com` that Gliuu Server would interact with -- ``` "GLUU_FQDN": "auth.example.com", "IS_GLUU_FQDN_REGISTERED": "Y", ``` Am I overthinking this, and it just needs to be the main site `example.com`?