How to Configure Networking in Ubuntu 20.04 with NetPlan



Overview


In this tutorial, you will learn how to configure networking in Ubuntu 20.04
with Netplan. You will learn how to set static IP addresses, DHCP addresses, as
well as how to configure DNS and Wifi.

Introduced back in 18.04, April 2018, networking was redone using a new system
called Netplan – a YAML based configuration network configuration system for 
NetworkManager and SystemD.


NetPlan Files


Network interfaces in Ubuntu 20.04 are configured in NetPlan YAML files, which 
are stored under /etc/netplan. The default file networking interfaces for a new
Ubuntu 20.04 install is /etc/netplan/00-installer-config.yaml.

To edit the default netplan file, use the following command.

sudo vi /etc/netplan/00-installer-config.yaml

Alternatively, a simpler text editor by the name of nano can be used instead
of vim.

sudo nano /etc/netplan/00-install-config.yaml


How to Set Static IP Address


The following is an example Netplan file with a network interface that has a
static IP address. The interface’s name is en01 and it has been assigned static
IP addresses 192.168.1.25/24 for IPv4, and 2001:1::1/64 for IPv6.

As both IPv4 and IPv6 have been assigned static IP addresses, each has a gateway
set too.

DNS Name servers are also defined in this file. We’ll cover DNS a little
further down in this tutorial.

network:
  version: 2
  renderer: networkd
  ethernets:
    en01:
      addresses:
      - 192.168.1.25/24
      - "2001:1::1/64"
      gateway4: 192.168.1.1
      gateway6: "2001:1::2"
      nameservers:
        addresses:
        - 8.8.8.8
        - 8.8.4.4

To apply changes to netplan you will need to reload your Netplan network
configurations.

sudo netplan apply


How to set DHCP Addresses


Dynamically addressed can be assigned for IPv4 and IPv6, provided your network
has a DHCP server.

The following example shows how to enable DHCP for both IPv4 and IPv6. To
enabled just one, you would remove the network IP version not needed.

network:
  version: 2
  renderer: networkd
  ethernets:
    en01:
      dhcp4: true
      dhcp6: true

To update your netplan configurations, run the netplan apply command.

sudo netplan apply


How to Set DNS


The following is an example of a network interface id0 with nameservers configured.

ethernets:
  en01:
    [...]
    nameservers:
      search: [lab, home]
      addresses: [8.8.8.8, "FEDC::1"]

search is a list of search domains, which are used when a non-fully qualified 
hostname is given. For example, if you were to ping server1 rather than 
server1.lab.  addresses is a list of IPv4 or IPv6 ip addresses for the DNS name
servers. IPv6 must be quoted. 


How to set WiFi Authentication


While WiFi is not something you would commonly configure Ubuntu server for, it 
it is prevalent enough you may consider using it in some use cases. To the 
following with walk you through configuring WPA and EAP wifi modes.

Systemd does not have native wifi support. In order for your network device to 
work with wifi you will need wpasupplicant installed.


Configuring WPA and EAP WiFi Connections


The most common home wifi configurations use mode WPA or EAP, while EAP is more
common in enterprise. These two modes use a basic form of authentication using 
a password or shared-key.

For home users, the WPA mode is the simplest to use with a compatible wifi
device. Devices that support WPA can automatically join wifi networks by
pressing the WPA button on a compatible wifi router.

To configure WPA or EAP on Ubuntu using Netplan, you would add the auth scalar
to your netplan configuration file. In the example below, we’ve added it to a 
ethernet interface named id0.

ethernets:
  id0:
    [...]
    access-points:
      mode: infrastructure
      bssid: mywifi
      band: 5GHz
      channel: 5
    auth:
      key-management: none | psk | eap 
      password: my-password-string

The access-points scalar sets how the wifi connection will be established.

mode set the mode type for your wifi network interface. For connecting to
access points the value should be set to infrastructure, which is the
default.
bassid is the name of your wifi connection, as configured on your access
point.
band is used to set the wireless band. It accepts two values: 5GHz and
2.4GHz. If left unset, the wifi endpoint and your network device will
automatically establish the best band. By setting this value you will force
the connection to use a specific band.
channel is used to set your wifi channel, and only takes affect if the band
property is set.


WPA and EAP connection modes accept the following configurations.

key-management sets how the supported key management mode.
        none to disable key management
        psk for WPA with pre-shared key, common for home wifi.
        eap for WPA with EAP, which is common for enterprise wifi networks.
password sets the pre-shared key or password for your wifi network, when
the mode is set to either psk or eap.


No related posts found
CategoriesAdministration