Network Connection issues in Recovery Mode

I’m trying to install Jetpack 2.3.1. After not using the TK1 for some time I tried to upgrade to 16.04 LTS via the standard ubuntu commands. Of course it didn’t succeed and it seem ok but to make sure I thought I would re-flash the TK1.
I can ssh to the TK1 when powered on but when I switch to recovery mode the TK1 doesn’t acquire an IP address. I’ve tried a static allocation using the MAC address but no luck.
I am following the installation instructions. I can see the TK1 using lsusb but it’s not on the local LAN. Any help is appreciated.

Got it. Just a timing issue - having TK1 on, program running & then rebooting to recovery mode.