How to configure the DHCPv6 client

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;
   }
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   Make sure to adapt the interface name (eno1) to the Internet interface name of your system and replace DUID with the DUID of your subnet.

How to autostart the DHCPv6 client during system boot

To enable 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
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   Tip:

   The path to the dhclient binaty 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 at each reboot of the machine:

   sudo systemctl enable dhclient.service
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