How to configure the dhclient

dhcpv6

duid

autostart

dhcp

dhclient

Reviewed on June 09, 2025

Before you start

To complete the actions presented below, you must have:

• A Dedibox account logged into the console
• A Dedibox dedicated server
• Requested a /48 IPv6 prefix

How to set the DUID of your subnet

1. Log into your server using SSH.

2. Open the file /etc/dhcp/dhclient6.conf in a text editor, for example: nano, and edit it as shown below:

   interface "eno1" {
       send dhcp6.client-id DUID;
   }

   Make sure to adapt the interface name (eno1) to the internet interface name of your system, and replace DUID with the DUID of your prefix.

How to autostart the DHCPv6 client during system boot

To enable the automatic start of the DHCPv6 client during system boot, a systemd service is required.

1. Log into your server using SSH.

2. Open the file /etc/systemd/system/dhclient.service in a text editor, for example: nano, and edit it as shown below:

   [Unit]
   Description=dhclient for sending DUID IPv6
   After=network-online.target
   Wants=network-online.target
   
   [Service]
   Restart=always
   RestartSec=10
   Type=forking
   ExecStart=/sbin/dhclient -cf /etc/dhcp/dhclient6.conf -6 -P -v eno1
   ExecStop=/sbin/dhclient -x -pf /var/run/dhclient6.pid
   
   [Install]
   WantedBy=network.target

   Tip

   The path to the dhclient binary may vary depending on your OS. To see the exact path for your system, use the following command: which dhclient.

3. Enable the service so it will start automatically at each reboot of the machine:

   sudo systemctl enable dhclient.service