Configuring a Static IP in Ubuntu

Last updated on 2024-01-25 15:15:05

Prerequisites

You need the following to configure a Static IP in Ubuntu for the Barracuda XDR Elastic Collector:

An Ubuntu installation
sudo rights to modify system configuration files
(Optional) – join to domain
Familiarity with the Vim text editor
Familiarity with Netplan (Required for newer Ubuntu environments)

For more information, see https:https://ubuntu.com/server/docs/network-configuration

When configure a static IP in Ubuntu, you'll need to follow these procedures:

To collect information on the current network
To configure the network
To test and apply your changes

To collect information on the current network

You'll need to collect details of the current network configuration so you can make the necessary changes to your configuration. In this procedure, you'll gather the following:

Available adapters
Respective IP information

You may also want to verify your default gateway configuration.

Log in as an Administrator with sudo rights.
Run the following command to collect the details of the available adapters and respective IP information:
sudo ip a
The results look like the following:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:e2:52:42 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.0.2/24 brd 192.168.0.255 scope global dynamic eth0
       valid_lft 3257sec preferred_lft 3257sec
    inet6 fe80::216:3eff:fee2:5242/64 scope link
       valid_lft forever preferred_lft forever
Make a note of the following to use in the next procedure:
- Network adapter (in the example above, the network adapter is eth0)
- Current IP address (in the example above, the IP address is 192.168.0.2/24)
  You can use the current IP address to configure a static IP, or you can choose a different one within the host IP range. The procedure below includes instructions for choosing a different IP.
Optionally, run the following command to verify your default gateway configuration:
sudo ip route show
The results look like the following:
default via 192.168.0.1 dev eth0 proto dhcp src 192.168.0.2 metric 100
Make a note of the default gateway (in the example above, the default gateway is 192.168.0.1).

To configure the network

Netplan is the default network management tool for the latest Ubuntu versions. Configuration files for Netplan are written using YAML and end with the extension .yaml.

One of the most common errors in configuration files is misplaced spaces. Be aware that configuration files read spaces as part of the syntax. Your file won't be read properly if you don't use the proper indentation.

Use the following command to list the files in the /etc/netplan directory:
ls /etc/netplan
Make a note of the existing configuration file if there is one.
Run one of the following commands:
- To update the configuration file:
  sudo vim /etc/netplan/[config.yaml], where [config.yaml] is the name of the existing configuration file from step 2 above.
- To create the configuration file is one doesn't exist:
  sudo vim /etc/netplan/01-netcfg.yaml
  01-netcfg.yaml will be the filename of the created configuration file.
Open the configuration file and edit the file with one of the following configurations:
- For Ubuntu environments Ubuntu Bionic 18.04 LTS and older:
  network:
  version: 2
  renderer: networkd
  ethernets:
  [ethX]:
        addresses:
          - [XXX.XXX.X.XXX/XX]
  gateway4: [XXX.XXX.X.X]
        nameservers:
            addresses: [X.X.X.X, X.X.X.X]
  Where [ethX] is your network adapter and [XXX.XXX.X.XXX/XX] is the current IP address from step 1;[XXX.XXX.X.X] is the default gateway from step 4, and [X.X.X.X, X.X.X.X] are the nameserver addresses.
- For newer Ubuntu environments:
  network:
  version: 2
  renderer: networkd
  ethernets:
  [ethX]:
        addresses:
          - [XXX.XXX.X.XXX/XX]
        routes:
          - to: default
            via: [XXX.XXX.X.X]
        nameservers:
            addresses: [X.X.X.X, X.X.X.X]
  Where [ethX] is your network adapter and [XXX.XXX.X.XXX/XX] is the current IP address from step 1;[XXX.XXX.X.X] is the default gateway from step 4, and [X.X.X.X, X.X.X.X] are the nameserver addresses.
Save the file.

To test and apply your changes

Run the following command:
sudo netplan try
Do one of the following:
- If this command runs with no errors, confirm you want to apply the settings.
- If the command runs with errors, fix the errors and repeat step 1.
Run the following command to verify the static IP has been applied:
sudo ip a
You will see results similar to the following:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
      valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:e2:52:42 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.0.100/24 brd 192.168.0.255 scope global dynamic eth0
       valid_lft 3257sec preferred_lft 3257sec
    inet6 fe80::216:3eff:fee2:5242/64 scope link
       valid_lft forever preferred_lft forever