Question about installing Jetpack 2.3

I’ve been looking over the videos for installing Jetpack 2.3 on a Jetson TX1 and find myself puzzled by the following steps - after downloading the Jetpack software onto the host machine, one must first specify how the Jetson accesses the internet and then put it in ‘Force Recovery Mode’ and connect it via USB to the host machine,.

Why are both steps necessary. I would’ve thought that everything needed is on the host machine and the Jetson TX1 can get everything it needs via the usb connection. Why does it need the internet connection at all?

You only need USB for flash. Network is entirely for adding additional packages over the net, and does not occur until the system reboots and is no longer in recovery mode.