If you are looking at getting external parties likes customers or vendors to log into your Dynamics system you are likely going to have a portal site setup for them to access. AX Enterprise Portal does allow you to set this up but you are likely going to want to use an external authentication provider to manage the user accounts to avoid having your internal IT setup an Active Directory to do this for all your external users. For these purposes AX supports Claims based authentication through Azure Access Control Namespaces. I’ve done a few posts on using the infrastructure once it’s setup but given that there are a lot of steps in the setup I thought it might be good to walk through end-to-end the setup.
Some previous posts
Here are a few comments on what to have ready for the configuration.
An additional item you will need to have ready is you login/subscription for Azure as you will need this to configure the Azure Access Control Namespaces. Also have some patience, there are a lot of little steps to get all the configuration up and running.