Networking with QEMU Ethernet

This page describes how to set up a virtual network between a (Linux) host and a Zephyr application running in QEMU.

In this example, the Socket Echo Server sample application from the Zephyr source distribution is run in QEMU. The Zephyr instance is connected to a Linux host using a tuntap device which is modeled in Linux as an Ethernet network interface.


On the Linux Host, fetch the Zephyr net-tools project, which is located in a separate Git repository:

git clone

Basic Setup

For the steps below, you will need two terminal windows:

  • Terminal #1 is terminal window with net-tools being the current directory (cd net-tools)
  • Terminal #2 is your usual Zephyr development terminal, with the Zephyr environment initialized.

When configuring the Zephyr instance, you must select the correct Ethernet driver for QEMU connectivity:

  • For qemu_x86, select Intel(R) PRO/1000 Gigabit Ethernet driver Ethernet driver. Driver is called e1000 in Zephyr source tree.
  • For qemu_cortex_m3, select TI Stellaris MCU family ethernet driver Ethernet driver. Driver is called stellaris in Zephyr source tree.
  • For mps2_an385, select SMSC911x/9220 Ethernet driver Ethernet driver. Driver is called smsc911x in Zephyr source tree.

Step 1 - Create Ethernet interface

Before starting QEMU with network connectivity, a network interface should be created in the host system.

In terminal #1, type:


You can tweak the behavior of the script. See various options by running like this:

./ --help

Step 2 - Start app in QEMU board

Build and start the Socket Echo Server sample application. In this example, the qemu_x86 board is used.

In terminal #2, type:

Using west:

west build -t run

Using CMake and ninja:

cmake -Bbuild -GNinja -DBOARD=qemu_x86 -DOVERLAY_CONFIG=overlay-e1000.conf samples/net/sockets/echo_server
ninja -Cbuild run