.. zephyr:code-sample:: dhcpv4-client
   :name: DHCPv4 client
   :relevant-api: dhcpv4 net_mgmt

   Start a DHCPv4 client to obtain an IPv4 address from a DHCPv4 server.

Overview

This application starts a DHCPv4 client, gets an IPv4 address from the DHCPv4 server, and prints address, lease time, netmask and router information to a serial console.

Requirements

• :ref:`networking_with_host`

Building and Running

Running DHCPv4 client in Linux Host

These are instructions for how to use this sample application using QEMU on a Linux host to negotiate IP address from DHCPv4 server running on Linux host.

To use QEMU for testing, follow the :ref:`networking_with_qemu` guide.

Here's a sample server configuration file '/etc/dhcp/dhcpd.conf' used to configure the DHCPv4 server:

log-facility local7;
default-lease-time 600;
max-lease-time 7200;

subnet 192.0.2.0 netmask 255.255.255.0 {
  range 192.0.2.10 192.0.2.100;
}

Use another terminal window to start up a DHCPv4 server on the Linux host, using this conf file:

$ sudo dhcpd -d -4 -cf /etc/dhcp/dhcpd.conf -lf /var/lib/dhcp/dhcpd.leases tap0

Run Zephyr samples/net/dhcpv4_client application in QEMU:

.. zephyr-app-commands::
   :zephyr-app: samples/net/dhcpv4_client
   :host-os: unix
   :board: qemu_x86
   :goals: run
   :compact:

Once DHCPv4 client address negotiation completed with server, details are shown like this:

[dhcpv4] [INF] main: In main
[dhcpv4] [INF] main_thread: Run dhcpv4 client
[dhcpv4] [INF] handler: Your address: 192.0.2.10
[dhcpv4] [INF] handler: Lease time: 600
[dhcpv4] [INF] handler: Subnet: 255.255.255.0
[dhcpv4] [INF] handler: Router: 0.0.0.0

To verify the Zephyr application client is running and has received an ip address by typing:

$ ping -I tap0 192.0.2.10

FRDM_K64F

These are instructions for how to use this sample application running on :ref:`frdm_k64f` board to negotiate IP address from DHCPv4 server running on Linux host.

Connect ethernet cable from :ref:`Freedom-K64F board <frdm_k64f>` to Linux host machine and check for new interfaces:

$ ifconfig

Add ip address and routing information to interface:

$ sudo ip addr add 192.0.2.2 dev eth1
$ sudo ip route add 192.0.2.0/24 dev eth1

Here's a sample server configuration file '/etc/dhcpd/dhcp.conf' used to configure the DHCPv4 server:

log-facility local7;
default-lease-time 600;
max-lease-time 7200;

subnet 192.0.2.0 netmask 255.255.255.0 {
  range 192.0.2.10 192.0.2.100;
}

Use another terminal window to start up a DHCPv4 server on the Linux host, using this conf file:

$ sudo dhcpd -d -4 -cf /etc/dhcp/dhcpd.conf -lf /var/lib/dhcp/dhcpd.leases eth1

Build Zephyr samples/net/dhcpv4_client application:

.. zephyr-app-commands::
   :zephyr-app: samples/net/dhcpv4_client
   :host-os: unix
   :board: frdm_k64f
   :goals: build flash
   :compact:

Once DHCPv4 client address negotiation completed with server, details are shown like this:

$ sudo screen /dev/ttyACM0 115200
[dhcpv4] [INF] main: In main
[dhcpv4] [INF] main_thread: Run dhcpv4 client
[dhcpv4] [INF] handler: Your address: 192.0.2.10
[dhcpv4] [INF] handler: Lease time: 600
[dhcpv4] [INF] handler: Subnet: 255.255.255.0
[dhcpv4] [INF] handler: Router: 0.0.0.0

To verify the Zephyr application client is running and has received an ip address by typing:

$ ping -I eth1 192.0.2.10

Arm FVP

• :ref:`fvp_baser_aemv8r`
• :ref:`fvp_base_revc_2xaemv8a`

This sample application running on Arm FVP board can negotiate IP address from DHCPv4 server running on Arm FVP, so there is no extra configuration that needed to do. It can be build and run directly.

Build Zephyr samples/net/dhcpv4_client application:

.. zephyr-app-commands::
   :zephyr-app: samples/net/dhcpv4_client
   :host-os: unix
   :board: fvp_baser_aemv8r
   :goals: build run
   :compact:

Once DHCPv4 client address negotiation completed with server, details are shown like this:

uart:~$
[00:00:00.060,000] <inf> phy_mii: PHY (0) ID 16F840

[00:00:00.170,000] <inf> phy_mii: PHY (0) Link speed 10 Mb, half duplex

[00:00:00.170,000] <inf> eth_smsc91x: MAC 00:02:f7:ef:37:16
*** Booting Zephyr OS build zephyr-v3.2.0-4300-g3e6505dba29e ***
[00:00:00.170,000] <inf> net_dhcpv4_client_sample: Run dhcpv4 client
[00:00:00.180,000] <inf> net_dhcpv4_client_sample: Start on ethernet@9a000000: index=1
[00:00:07.180,000] <inf> net_dhcpv4: Received: 172.20.51.1
[00:00:07.180,000] <inf> net_dhcpv4_client_sample:    Address[1]: 172.20.51.1
[00:00:07.180,000] <inf> net_dhcpv4_client_sample:     Subnet[1]: 255.255.255.0
[00:00:07.180,000] <inf> net_dhcpv4_client_sample:     Router[1]: 172.20.51.254
[00:00:07.180,000] <inf> net_dhcpv4_client_sample: Lease time[1]: 86400 seconds