Network not starting after boot

[Free the NAS]

Just built my first TrueNAS system. I'm new to FreeBSD but not Unix or NASes in general (I've been running an OMV server for over five years, and I've been working with Unix since the late 1980s). The install went fine, but whenever it's booted, it shows the message "The web interface could not be accessed" and the system can not be accessed via the web UI or SSH from another host on the network. Only after I choose Configure Network Interface from the initial boot menu does it become accessible.

How can I make the network start automatically?

 

[Free the NAS]

OK, I figured this out on my own; it was due to a flakey port on the network switch it was connected to.