Share a USB hard disk on your network in AirPort Utility on Mac
You can use a shared USB hard disk on your network to store files and data. You can connect to the disk in a variety of ways:
If you’re using an AirPort Time Capsule: It already contains an internal disk. If you want, you can connect additional USB disks to the USB port on your AirPort Time Capsule.
If you’re using an AirPort Extreme: You can connect an additional USB hard disk to the USB port on your base station.
If you connect a USB hub to an AirPort Time Capsule or AirPort Extreme: You can connect several hard disks to the hub.
Note: AirPort Utility doesn’t support formatting disks. Format the hard disk using your computer. On a Mac, format the hard disk using macOS Extended format (also called HFS+). On a Windows computer, use FAT32.
Plug the hard disk in to the base station’s USB port .
Select “Enable file sharing” to let users share files on the disk, and “Share disks over WAN” if you want to provide remote access to the disk over the WAN port.
Do one of the following to secure the disk:
Secure the disk with a disk password: Click the Secure Shared Disks pop-up menu, then choose “With a disk password.” Enter a disk password, then enter it again to verify it.
Secure the disk with your base station password: Click the Secure Shared Disks pop-up menu, then choose “With device password.”
If you want to secure the disk with individual user accounts, follow the instructions in Secure a connected hard disk.
If you want your new password to be in your macOS keychain, select “Remember this password in my keychain.”
When you’re done, click Update to save your changes.