Once you've used IT:AD:SSH-KEYGEN to create IT:AD:SSH Key pairs, you use IT:AD:SSH-ADD to register the keys, and associate them to the url of a remote service (such as IT:AD:BitBucket).

The association between Keys and url is used by your SSHAGENT so that when IT:AD:Git (or other tool) invokes IT:AD:SSH to communicate with a remote server, it knows which key pair to use.

The process of setting up SSH is more or less the following: