.. _echo-server-sample:
Echo Server
###########
Overview
********
The echo-server sample application for Zephyr implements a UDP/TCP server
that complements the echo-client sample application: the echo-server listens
for incoming IPv4 or IPv6 packets (sent by the echo client) and simply sends
them back.
The source code for this sample application can be found at:
:file:`samples/net/echo_server`.
Requirements
************
- :ref:`networking_with_qemu`
Building and Running
********************
There are multiple ways to use this application. One of the most common
usage scenario is to run echo-server application inside QEMU. This is
described in :ref:`networking_with_qemu`.
There are configuration files for different boards and setups in the
echo-server directory:
- :file:`prj.conf`
Generic config file, normally you should use this.
- :file:`overlay-frdm_k64f_cc2520.conf`
This overlay config enables support for IEEE 802.15.4 CC2520 and frdm_k64f
- :file:`overlay-frdm_k64f_mcr20a.conf`
This overlay config enables support for IEEE 802.15.4 mcr20a and frdm_k64f
- :file:`overlay-ot.conf`
This overlay config enables support for OpenThread
- :file:`overlay-enc28j60.conf`
This overlay config enables support for enc28j60 ethernet board. This
add-on board can be used for example with Arduino 101 board.
- :file:`overlay-cc2520.conf`
This overlay config enables support for IEEE 802.15.4 cc2520 chip.
- :file:`overlay-bt.conf`
This overlay config enables support for Bluetooth IPSP connectivity.
- :file:`overlay-qemu_802154.conf`
This overlay config enables support for two QEMU's when simulating
IEEE 802.15.4 network that are connected together.
- :file:`overlay-tls.conf`
This overlay config enables support for TLS.
- :file:`overlay-netusb.conf`
This overlay config enables support for Ethernet over USB setup with
supported boards. The setup is described in :ref:`usb_device_networking_setup`
Build echo-server sample application like this:
.. zephyr-app-commands::
:zephyr-app: samples/net/echo_server
:board: <board to use>
:conf: <config file to use>
:goals: build
:compact:
Example building for the FRDM-K64F with TI CC2520 support:
.. zephyr-app-commands::
:zephyr-app: samples/net/echo_server
:host-os: unix
:board: frdm_k64f
:conf: "prj.conf overlay-frdm_k64f_cc2520.conf"
:goals: run
:compact:
Make can select the default configuration file based on the BOARD you've
specified automatically so you might not always need to mention it.
Running echo-client in Linux Host
=================================
There is one useful testing scenario that can be used with Linux host.
Here echo-server is run in QEMU and echo-client is run in Linux host.
To use QEMU for testing, follow the :ref:`networking_with_qemu` guide.
Run echo-server application in QEMU:
.. zephyr-app-commands::
:zephyr-app: samples/net/echo_server
:host-os: unix
:board: qemu_x86
:goals: run
:compact:
In a terminal window:
.. code-block:: console
$ sudo ./echo-client -i tap0 2001:db8::1
Note that echo-server must be running in QEMU before you start the
echo-client application in host terminal window.
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