Any drives installed into the system can be protected, too. The removable bays can be locked in place and although the locks themselves wouldn't do much to thwart Neal Caffrey, they should provide a decent mental barrier to less masterly criminals. On the software side 256-bit AES RAID volume encryption should keep data stored on the N4200 safe, even in the event of a disk being pinched. An encryption key, placed on a USB drive, plugged into system, must be present when booting for data to be accessible - in other words do not lose that key!
Another useful ability with drives is to allocate one as a hot spare for a RAID array. So if, for example, you add three four drives you can configure three of them in RAID 5, with the fourth automatically replacing any of the others in the event of a failure. Also on the plus side is support for hot-swapping of drives and RAID extension.
Once the storage space within the N4200 is configured, there are several ways to actually use it. Capacity can be allocated either as iSCSI targets, or as simple volumes. All the protocols you'd expect to be present are supported, including Samba, CIFS, AFP, NFS and FTP. The latter has the benefit of offering bandwidth control, which is useful for curtailing particular users that might impede others if left unchecked. Building and rebuilding arrays, checking their integrity if necessary, and formatting drives, is handled with pleasing speed.
Options are aplenty to help you keep your data safe, with Snapshots, a Recycle Bin and backups to other networked devices (as well as external drives, as previously mentioned) on offer. Thecus bundles backup software with the N4200, which works as expected.
The N4200 sports two Gigabit Ethernet ports, marked LAN and WAN. These can be configured to work separately - making the N4200 accessible to a local network and the Internet via router, for example - or aggregated, 802.3ad (read: bonded), load balanced or failover modes. If you don't know what those are, or why you’d want to use them, then you probably don't need to.