Native Posix Ethernet

Overview

The eth_native_posix sample application for Zephyr creates a zeth network interface to the host system. One can communicate with Zephyr via this network interface.

The source code for this sample application can be found at: samples/net/eth_native_posix.

Building And Running

To build the eth_native_posix sample application, follow the steps below.

cd $ZEPHYR_BASE/samples/net/eth_native_posix
mkdir build && cd build
cmake -GNinja -DBOARD=native_posix -DCONF_FILE=<config file to use> ..
ninja

Normally one needs extra privileges to create and configure the TAP device in the host system. Use sudo to execute the Zephyr process with admin privileges, like this:

sudo --preserve-env=ZEPHYR_BASE make run

If the sudo --preserve-env=ZEPHYR_BASE gives an error, just use sudo --preserve-env instead:

If you want to connect two Zephyr instances together, you can do it like this:

Create two Zephyr config files prj1.conf and prj2.conf. You can use samples/net/eth_native_posix/prj.conf as a base.

Set prj1.conf IP address configuration like this:

CONFIG_NET_CONFIG_MY_IPV6_ADDR="2001:db8:100::1"
CONFIG_NET_CONFIG_PEER_IPV6_ADDR="2001:db8:100::2"
CONFIG_NET_CONFIG_MY_IPV4_ADDR="198.51.100.1"
CONFIG_NET_CONFIG_PEER_IPV4_ADDR="198.51.100.2"
CONFIG_NET_CONFIG_MY_IPV4_GW="203.0.113.1"
CONFIG_ETH_NATIVE_POSIX_RANDOM_MAC=n
CONFIG_ETH_NATIVE_POSIX_MAC_ADDR="00:00:5e:00:53:64"
CONFIG_ETH_NATIVE_POSIX_SETUP_SCRIPT="echo"
CONFIG_ETH_NATIVE_POSIX_DRV_NAME="zeth.1"

Set prj2.conf IP address configuration like this:

CONFIG_NET_CONFIG_MY_IPV6_ADDR="2001:db8:200::1"
CONFIG_NET_CONFIG_PEER_IPV6_ADDR="2001:db8:200::2"
CONFIG_NET_CONFIG_MY_IPV4_ADDR="203.0.113.1"
CONFIG_NET_CONFIG_PEER_IPV4_ADDR="203.0.113.2"
CONFIG_NET_CONFIG_MY_IPV4_GW="198.51.100.1"
CONFIG_ETH_NATIVE_POSIX_RANDOM_MAC=n
CONFIG_ETH_NATIVE_POSIX_MAC_ADDR="00:00:5e:00:53:c8"
CONFIG_ETH_NATIVE_POSIX_SETUP_SCRIPT="echo"
CONFIG_ETH_NATIVE_POSIX_DRV_NAME="zeth.2"

Then compile and run two Zephyr instances (if sudo --preserve-env=ZEPHYR_BASE gives an error, just use sudo --preserve-env instead):

mkdir -p build1/native_posix
cmake -DCONF_FILE=prj1.conf -DBOARD=native_posix -Bbuild1/native_posix -H.
make -s -C build1/native_posix
sudo --preserve-env=ZEPHYR_BASE make -s -C build1/native_posix run

mkdir -p build2/native_posix
cmake -DCONF_FILE=prj2.conf -DBOARD=native_posix -Bbuild2/native_posix -H.
make -s -C build2/native_posix
sudo --preserve-env=ZEPHYR_BASE make -s -C build2/native_posix run

Bridge the two Zephyr instances together:

sudo brctl addbr zeth-br
sudo brctl addif zeth-br zeth.1
sudo brctl addif zeth-br zeth.2
sudo ifconfig zeth-br up

After this, you are able to ping device 1 from device 2 in net-shell:

# In device 1
net ping 2001:db8:200::1
net ping 203.0.113.1

# In device 2
net ping 2001:db8:100::1
net ping 198.51.100.1

Note that in this setup you cannot access these two Zephyr devices from your host. If you want to do that, then you could create a new network interface with proper IP addresses and add that interface to the Zephyr bridge.