Configuring DHCPCD on a Scaleway Dedibox

dhcpcd is an open-source DHCP client, supporting both IPv4, and IPv6. The feature-rich software can be used to configure and automate network-related parameters of your computer using the DHCP protocol.

In this tutorial, you will learn how to configure your IPv6 subnet with DHCPCD on a Scaleway Dedibox dedicated server.

Before you start

To complete the actions presented below, you must have:

• A Dedibox account logged into the console
• A [Dedibox dedicated server] (https://www.scaleway.com/en/dedibox)
• Root access to the server

Installing DHCPCD

1. Change the root account of your server by using su and the password of the root user.
2. For Debian and Ubuntu, update the apt package manager repositories, then upgrade the software already installed on the machine to the latest version available in the repositories:
   apt update && apt upgrade -y

3. For Arch Linux, update the pacman package manager repositories.
   pacman -Syu

4. For Debian & Ubuntu, install DHCPCD using the apt package manager:
   apt install dhcpcd5

5. For Arch Linux, install DHCPCD using the Arch Linux package manager:
   pacman -S dhcpcd

Configuring DHCPCD

1. Open the DHCPCD configuration file located at /etc/dhcpcd.conf in a text editor of your choice and edit it as follows:

   # Allow users of this group to interact with dhcpcd via the control socket.
   #controlgroup wheel
   
   # Inform the DHCP server of our hostname for DDNS.
   #hostname
   
   # This parameter allows only selected interfaces to use the client
   allowinterfaces eno*
   
   # Use the hardware address of the interface for the Client ID.
   #clientid
   # or
   # Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as per RFC4361.
   # Some non-RFC compliant DHCP servers do not reply with this set.
   # In this case, comment out duid and enable clientid above.
   duid
   
   # Persist interface configuration when dhcpcd exits.
   persistent
   
   # vendorclassid is set to blank to avoid sending the default of
   # dhcpcd-<version>:<os>:<machine>:<platform>
   vendorclassid
   
   # A list of options to request from the DHCP server.
   option classless_static_routes
   # Respect the network MTU. This is applied to DHCP routes.
   option interface_mtu
   
   # Request a hostname from the network
   option host_name
   
   # Most distributions have NTP support.
   #option ntp_servers
   
   # Rapid commit support.
   # Safe to enable by default because it requires the equivalent option set
   # on the server to actually work.
   option rapid_commit
   
   # A ServerID is required by RFC2131.
   require dhcp_server_identifier
   
   # Generate SLAAC address using the Hardware Address of the interface
   #slaac hwaddr
   # OR generate Stable Private IPv6 Addresses based from the DUID
   #slaac private
   # Do not attempt to obtain an IPv4LL address if we failed to get one via DHCP.  See RFC 3927.
   noipv4ll
   
   # Specify the network interface to which the following configurations apply
   interface eno1
   # Enable IPv6 Router Solicitation (RS) messages on the specified interface
   ipv6rs
   # Request an IPv6 Non-Temporary Address (IA_NA) from the DHCPv6 server
   ia_na 1
   # Configure a static IPv6 address on the interface
   # Replace the "xxxx", "xxx", and "x" placeholder values
   static ip6_address=2001:bc8:xxxx:xxx::x/64

2. Write the [DUID] of your subnet in the file /var/lib/dhcpcd/duid using a text editor of your choice, for example nano:

   nano /var/lib/dhcpcd/duid

3. Enable the DHCPCD service to be started automatically during system boot.

   systemctl enable dhcpcd.service

4. Start the service manually.

   systemctl start dhcpcd.service

5. Verify the status of the service.

   systemctl status dhcpcd.service

   You should see an output similar to the following:

   ● dhcpcd.service - DHCP Client Daemon
     Loaded: loaded (/lib/systemd/system/dhcpcd.service; enabled; vendor preset: enabled)
     Active: active (running) since Mon 2021-03-15 15:30:03 CET; 14s ago
       Docs: man:dhcpcd(8)
     Process: 22352 ExecStart=/usr/sbin/dhcpcd (code=exited, status=0/SUCCESS)
   Main PID: 22368 (dhcpcd)
       Tasks: 1 (limit: 4696)
     Memory: 1.5M
     CGroup: /system.slice/dhcpcd.service
             └─22368 /usr/sbin/dhcpcd
   
   Mar 15 15:30:13 sd-160847 dhcpcd[22368]: enp1s0: pltime 604800 seconds, vltime 2592000 seconds
   Mar 15 15:30:13 sd-160847 dhcpcd[22368]: enp1s0: sending NA for 2001:bc8:XXXX/64
   Mar 15 15:30:13 sd-160847 dhcpcd[22368]: enp1s0: executing `/lib/dhcpcd/dhcpcd-run-hooks' ROUTERADVERT
   Mar 15 15:30:14 sd-160847 dhcpcd[22368]: enp1s0: sending NA for 2001:bc8:XXXX/64
   Mar 15 15:30:15 sd-160847 dhcpcd[22368]: enp1s0: sending NA for 2001:bc8:1600:XXXX/64
   Mar 15 15:30:16 sd-160847 dhcpcd[22368]: enp1s0: Router Advertisement from fe80::XXXX
   Mar 15 15:30:16 sd-160847 dhcpcd[22368]: enp1s0: adding address 2001:bc8:XXXX/64
   Mar 15 15:30:16 sd-160847 dhcpcd[22368]: enp1s0: pltime 604800 seconds, vltime 2592000 seconds
   Mar 15 15:30:16 sd-160847 dhcpcd[22368]: enp1s0: sending NA for 2001:bc8:XXXX/64
   Mar 15 15:30:16 sd-160847 dhcpcd[22368]: enp1s0: executing `/lib/dhcpcd/dhcpcd-run-hooks' ROUTERADVERT

Your server is now ready to communicate with IPv6. For more information about IPv6 at Scaleway Dedibox, refer to our dedicated documentation.