The American Registry for Internet Numbers (ARIN) is a registry that manages and distributes IP addresses for Canada, the US, and several surrounding countries. They are the organization responsible for allocating IP addresses to telecommunications providers.

If you’re seeking a new static IP address with your Metronet service, you do not need to register with ARIN to acquire that, as Metronet manages the IP addresses that have been allocated to it by ARIN.

You can read more about how ARIN allocates IP addresses here.