Configuring Static IP address on Ubuntu Server

 

Configuring Static IP address on Ubuntu Server

The newer versions of Ubuntu uses ‘Predictable Network Interface Names’ that, by default, start with en[letter][number].

The first step is to identify the name of the ethernet interface you want to configure. To do so use the ip link command, as shown below:

ip link

The command will print a list of all the available network interfaces. In this case, the name of the interface is ens3:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
3: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 56:00:00:60:20:0a brd ff:ff:ff:ff:ff:ff

Netplan configuration files are stored in the /etc/netplan directory and have the extension .yaml. You’ll probably find one or two YAML files in this directory. The file may differ from setup to setup. Usually, the file is named either 01-netcfg.yaml, 50-cloud-init.yaml, or NN_interfaceName.yaml, but in your system it may be different.

Open the YAML configuration file with your text editor :

sudo nano /etc/netplan/01-netcfg.yaml

/etc/netplan/01-netcfg.yaml

network:
  version: 2
  renderer: networkd
  ethernets:
    ens3:
      dhcp4: yes

Before changing the configuration, let’s explain the code in a short.

Each Netplan Yaml file starts with the network key that has at least two required elements. The first required element is the version of the network configuration format, and the second one is the device type. The device type can be ethernets, bonds, bridges, or vlans.

The configuration above also includes the renderer type. Out of the box, if you installed Ubuntu in server mode, the renderer is configured to use networkd as the back end.

Under the device’s type (in this case ethernets), you can specify one or more network interfaces. In this example, we have only one interface ens3 that is configured to obtain IP addressing from a DHCP server dhcp4: yes.

To assign a static IP address to ens3 interface, edit the file as follows:

• Set DHCP to dhcp4: no.
• Specify the static IP address 192.168.121.199/24. Under addresses: you can add one or more IPv4 or IPv6 IP addresses that will be assigned to the network interface.
• Specify the gateway gateway4: 192.168.121.1
• Under nameservers, set the IP addresses of the nameservers addresses: [8.8.8.8, 1.1.1.1]

/etc/netplan/01-netcfg.yaml

network:
  version: 2
  renderer: networkd
  ethernets:
    ens3:
      dhcp4: no
      addresses:
        - 192.168.121.199/24
      gateway4: 192.168.121.1
      nameservers:
          addresses: [8.8.8.8, 1.1.1.1]

When editing Yaml files, make sure you follow the YAML code indent standards. If there are syntax errors in the configuration, the changes will not ne applied.

Once done save and close the file and apply the changes with:

sudo netplan apply

Verify the changes by typing:

ip addr show dev ens3

3: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 56:00:00:60:20:0a brd ff:ff:ff:ff:ff:ff
    inet 192.168.121.199/24 brd 192.168.121.255 scope global dynamic ens3
       valid_lft 3575sec preferred_lft 3575sec
    inet6 fe80::5054:ff:feb0:f500/64 scope link 
       valid_lft forever preferred_lft forever

That’s it! You have assigned a static IP to your Ubuntu server.