Switch network configuration from ifupdown to netplan

Last update: March 04 2024

Switch network configuration from ifupdown to netplan

In cloud servers created from pre-built images of Ubuntu 18.04, 20.04, and 22.04, ifupdown is used by default to configure the network.

You can switch network configuration from ifupdown to netplan — the procedure depends on whether the cloud-init agent is installed in the image.

If cloud-init is set⁠

1. Connect to server.

2. Remove ifupdown and restart the server:

   apt purge ifupdown && reboot now

3. The cloud-init agent will independently configure the network for netplan.

If cloud-init is not installed⁠

1. Connect to server.

2. Create a configuration file for netplan (/etc/neplan/config.yaml). If necessary, you can add routes in the routes block:

   Public IP address with DHCP

   network:
       version: 2
       ethernets:
           eth0:
               dhcp4: true
               match:
                   macaddress: <mac_address>
               mtu: 1500
               set-name: eth0

   Specify <mac_address> — MAC address of the interface.

   Public IP address without DHCP

   network:
       version: 2
       ethernets:
           eth0:
               addresses:
               - <private_subnet>
               match:
                   macaddress: <mac_address>
               mtu: 1500
               nameservers:
                   addresses: <nameservers_addresses>
               routes:
               - to: <destination_subnet>
                   via: <gateway>
               set-name: eth0

   Specify:

   • <private_subnet> — CIDR of the private subnet;
   • <mac_address> — MAC address of the interface;
   • <nameservers_addresses> — DNS servers. DNS Selectel: 188.93.16.19, 188.93.17.19;
   • <destination_subnet> is the CIDR of the destination subnet, for example 0.0.0.0.0/0;
   • <gateway> — IP address of the private subnet gateway, can be viewed in control panel under Cloud Platform → Servers → server page → Ports tab.

   Private network and /29 with DHCP

   network:
       version: 2
       ethernets:
           eth0:
               dhcp4: true
               match:
                   macaddress: <mac_address>
               mtu: 1500
               set-name: eth0
           eth1:
               addresses:
               - <ip_address>/29
               match:
                   macaddress: <mac_address>
               mtu: 1500
               nameservers:
                   addresses: <nameservers_addresses>
               routes:
               - to: <destinantion_subnet>
                   via: <gateway>
               set-name: eth1

   Specify:

   • <mac_address> — MAC address of the interface;
   • <ip_address> — IP address of subnet /29;
   • <nameservers_addresses> — DNS servers. DNS Selectel: 188.93.16.19, 188.93.17.19;
   • <destination_subnet> is the CIDR of the destination subnet, for example 0.0.0.0.0/0;
   • <gateway> — IP address of the gateway.

   Private network and /29 without DHCP

   network:
       version: 2
       ethernets:
           eth0:
               addresses:
               - <private_subnet>
               match:
                   macaddress: <mac_address>
               mtu: 1500
               nameservers:
                   addresses: <nameservers_addresses>
               routes:
               - to: <destination_subnet>
                   via: <gateway>
               set-name: eth0
           eth1:
               addresses:
               - <ip_address>/29
               match:
                   macaddress: <mac_address>
               mtu: 1500
               nameservers:
                   addresses: <nameservers_addresses>
               routes:
               - to: <destination_subnet>
                   via: <gateway>
               set-name: eth1

   Specify:

   • <private_subnet> — CIDR of the private subnet;
   • <mac_address> — MAC address of the interface;
   • <nameservers_addresses> — DNS servers. DNS Selectel: 188.93.16.19, 188.93.17.19;
   • <destination_subnet> is the CIDR of the destination subnet, for example 0.0.0.0.0/0;
   • <gateway> — IP address of the gateway;
   • <ip_address> — IP address of subnet /29.

3. Check the syntax:

   sudo netplan try

4. Apply the settings:

   sudo netplan apply