Configure networking#

Hostnames and IP addresses#

Update the server’s Pillar file:

network:
  host_id: ocp12
  ipv4: 198.51.100.34
  ipv6: 2001:db8::12

ipv6 is optional.

Linux networking#

systemd-networkd#

systemd-networkd is a system daemon to configure networking, and is our preferred solution for Linode instances. The configuration is written to /etc/systemd/network/05-eth0.network. A configuration template is available for Linode.

Linode template#

This configuration disables automatic IP configuration and configures static networking on IPv4 and IPv6.

Note

By default, a Linode server listens on – and prefers traffic to – its default IPv6 address. We provision IPv6 /64 blocks for each server to improve IP reputation and email deliverability.

Email template

Open a support ticket with Linode to request an IPv6 /64 block, replacing ocpXX with the Linode instance’s ID:

Hello,

Please can you provision an IPv6 /64 block for my server ocpXX.open-contracting.org.

Thank you,

A /64 block is requested, because spam blocklists use /64 ranges.

Update the server’s Pillar file:

network:
  host_id: ocp12
  ipv4: 198.51.100.34
  ipv6: "2001:db8::"
  networkd:
    template: linode
    addresses:
      - 2001:db8::/64
    gateway4: 198.51.100.1

To fill in the above, from the Network tab on the Linode’s page, collect:

ipv4: The Address with a Type of IPv4 – Public
gateway4: The Default Gateway with a Type of IPv4 – Public
addresses: Other IP addresses attached to your instance (if any). Include the subnet block suffix, e.g.: /64

Custom template#

Warning

Only use a custom template if your needs are not met by any other template.

In the server’s Pillar file, set network.networkd.template to custom and set network.networkd.configuration:

[Match]
Name=eth0

[Network]
DHCP=no
DNS=203.0.113.1 203.0.113.2 2001:db8::32 2001:db8::64
Domains=open-contracting.org
IPv6PrivacyExtensions=false
IPv6AcceptRA=false

Address=198.51.100.34/24
Address=2001:db8::12/64

Gateway=Address=198.51.100.1
Gateway=fe80::1

Netplan#

Netplan uses YAML files for configuration. The configuration is written to /etc/netplan/10-salt-networking.yaml. A configuration template is available for Linode.

Note

This step is optional. Only override a Netplan configuration if necessary. For example, Hetzner’s installimage script creates a configuration file that works as-is.

In the server’s Pillar file, set network.netplan.template to custom and set network.netplan.configuration:

network:
  host_id: ocp12
  ipv4: 198.51.100.34
  ipv6: 2001:db8::12
  netplan:
    template: custom
    configuration: |
      network:
        version: 2
        renderer: networkd
        ethernets:
          eth0:
            addresses:
              - 198.51.100.34/32
              ...

Time servers#

systemd-timesyncd synchronizes the local system clock with remote NTP servers.

You should select NTP servers from the NTP Pool Project that are close to the server’s location, in order to mitigate network latency and improve time accuracy.

For example, to use the NTP servers in Finland, add to the server’s Pillar file:

ntp:
  - 0.fi.pool.ntp.org
  - 1.fi.pool.ntp.org
  - 2.fi.pool.ntp.org
  - 3.fi.pool.ntp.org

By default, the NTP servers in the UK are used.