Is there a way to have multiple partitions on a hard drive plugged into an Airport Extreme? I have a 3TB hard drive, and would like a 2TB partition for storage, time machine backups (mac formatted), and then a 1TB ntfs formatted for stuff accessible to windows computers. However, if I have more than one partition, the disk doesn't show up at all in Airport Utility or in Finder. Is there a way around this limitation?
No, this isn't possible. According to Apple Support:
Time Machine can’t back up to an external disk connected to an AirPort Extreme, or to an iPod, iDisk, or disk formatted for Windows.
However, the same KB also notes that:
You can use Time Machine with a Time Capsule, and with USB, FireWire, and Thunderbolt disks. The backup disk can be directly connected to your computer or be on a network. If the backup disk has been divided into partitions, you can use one of the partitions.
You just can't have that drive hooked up to the Airport Extreme.