extremely long bootup with r24.1 jetson tx1 and no network connected

The jetson tx1 with r24.1 takes a very long time (250 seconds) to boot if no network is connected. Why is this and what can be done to improve it?

I suspect it is set to wait for a DHCP response for network setup, and then times out and finally continues.

I deal with Fedora networking, so I’m not sure on Ubuntu what to set, but basically it involves making the network connection optional so it continues without waiting. This would be standard on all of the Ubuntu 14.04 LTS installs, so it isn’t actually specific to Jetson. Probably something in NetworkManager, but I do not know specifics.

I’m pretty sure that’s not the reason because I set the network to static rather than dhcp.

I’ve discovered that the system does this when I uninstall network manager. I’ve done this because it’s too difficult to manage the network from within our application when network manager is running. So I removed it and just handle the network with the /etc/network/interfaces.d scripts.

Does anybody have a suggestion?

There may still be dhcp issues on wireless, I find Ubuntu somewhat frustrating for network configuration when doing anything non-default. Also, see this regarding firmware which may cause odd wireless network issues:
https://devtalk.nvidia.com/default/topic/901180/jetson-tx1/my-jetson-tx1-is-not-able-to-connect-to-wifi/

It may just be a case of removing or renaming the firmware mentioned in the above URL.

I discovered that if I set the scripts to use allow-hotplug rather than auto this fixes the problem.

For example, instead of using

auto eth0

in an interfaces.d configuration file I use

allow-hotplug eth0