.. _networking_with_native_posix: Networking with native_posix board ################################## .. contents:: :local: :depth: 2 This page describes how to set up a virtual network between a (Linux) host and a Zephyr application running in a native_posix board. In this example, the :zephyr:code-sample:`sockets-echo-server` sample application from the Zephyr source distribution is run in native_posix board. The Zephyr native_posix board instance is connected to a Linux host using a tuntap device which is modeled in Linux as an Ethernet network interface. Prerequisites ************* On the Linux Host, fetch the Zephyr ``net-tools`` project, which is located in a separate Git repository: .. code-block:: console git clone https://github.com/zephyrproject-rtos/net-tools Basic Setup *********** For the steps below, you will need three 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. * Terminal #3 is the console to the running Zephyr native_posix instance (optional). Step 1 - Create Ethernet interface ================================== Before starting native_posix with network emulation, a network interface should be created. In terminal #1, type: .. code-block:: console ./net-setup.sh You can tweak the behavior of the net-setup.sh script. See various options by running ``net-setup.sh`` like this: .. code-block:: console ./net-setup.sh --help Step 2 - Start app in native_posix board ======================================== Build and start the ``echo_server`` sample application. In terminal #2, type: .. zephyr-app-commands:: :zephyr-app: samples/net/sockets/echo_server :host-os: unix :board: native_posix :goals: run :compact: Step 3 - Connect to console (optional) ====================================== The console window should be launched automatically when the Zephyr instance is started but if it does not show up, you can manually connect to the console. The native_posix board will print a string like this when it starts: .. code-block:: console UART connected to pseudotty: /dev/pts/5 You can manually connect to it like this: .. code-block:: console screen /dev/pts/5