Netstack3 Hacking HOWTO

This document describes how to run Netstack3, as well as a few possible dev workflows. The instructions are for how to set up QEMU, but are also applicable to real hardware.

Running Alongside Default Netstack

The following instructions here are for running Netstack3 alongside the default netstack on a separate interface. This is currently the recommended method of running Netstack3.

(Step 1) QEMU Setup

First, set up two interfaces for QEMU to use (you only need to do this once per boot of host machine):

sudo ip tuntap add dev qemu mode tap user $USER
sudo ip tuntap add dev qemu-extra mode tap user $USER
sudo ip link set qemu up
sudo ip link set qemu-extra up

Assign an IPv4 address for the qemu-extra interface so that you can ping from it later:

sudo ip addr add dev qemu-extra 192.168.4.1/24

Start Qemu with networking support:

fx qemu -N

At this point you should be able to fx shell and resolve the default netstack interface address with fx get-device-addr.

(Step 2) enclosed_runner Setup

Follow the instructions in the enclosed_runner documentation to run Netstack3 on the second ethernet interface. Note that the instructions above assigned 192.168.4.1/24 to qemu-extra so the address assigned to Netstack3 through enclosed_runner should also be in this subnet. If you're successful, you should be able to ping the address assigned to Netstack3 (presumably 192.168.4.x) from the host machine.