Prep aring the Armory for installation:

All that is needed for lightningd to communicate with a remote bitcoind is bitcoin-cli , which drastically reduces the time needed to build on the Armory. Cross-compiliation is possible, but that is out of the scope of this guide. In order to build only bitcoin-cli , the Bitcoin code needs to be pulled from its Github repository. But, before that can be done, packet forwarding must be enabled on the host device (the device the Armory is plugged into).

Networking:

The Armory (if using the official Debian base image), when plugged in and booted, creates a virtual interface that emulates an Ethernet connection. Once configured, the Armory and its USB host can communicate with each other as if they were on the same LAN (since they technically are). It is up to the USB host to allow the Armory’s packets to be forwarded or not, which if allowed enables the Armory to open Lightning Network channels with other nodes outside of the local network. Packet forwarding is also required to install build tools and dependencies.

Windows:

Instructions for enabling packet forwarding (also known as Connection Sharing) for Windows 7, 8, and 10 can be found here.

MacOS:

MacOS instructions can be found here.

Linux:

Note: On Ubuntu 16.04, the Network Manager did not interfere. Other distributions’ configurations might, however.

From the Linux instructions: