Setup Ubuntu Static IP

To configure a static IP address on Ubuntu, you will need to edit the network (netplan) configuration files.

Step 1: Find your network interface

ip addr

Look for the interface that is currently connected to the network. For my cased, it is wlo1.

kc@kchomelab:~$ ip addr
3: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether a0:29:42:00:3c:78 brd ff:ff:ff:ff:ff:ff
    altname wlp0s20f3
    inet 192.168.0.20/24 brd 192.168.0.255 scope global dynamic noprefixroute wlo1
       valid_lft 86009sec preferred_lft 86009sec
    inet6 2001:e68:545b:1e09:331:a36c:d781:b2ad/64 scope global temporary dynamic 
       valid_lft 209331sec preferred_lft 85891sec
    inet6 2001:e68:545b:1e09:20ce:6713:d2e1:733a/64 scope global dynamic mngtmpaddr noprefixroute 
       valid_lft 209331sec preferred_lft 122931sec
    inet6 fe80::c7b2:63f6:791c:7ef9/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

Step 2: Create or Edit the netplan configuration file

Let's first list the files in the /etc/netplan/ directory. You should see a lists of YAML files. You can either create a new file or edit an existing one.

kc@kchomelab:~$ ls /etc/netplan
01-network-manager-all.yaml  90-NM-904e969d-0545-4cb6-98f5-3b150b90657e.yaml
50-cloud-init.yaml

For my case, I will create a new file called 99-static-ip.yaml, there's because by using a higher prefix like 99-, it ensures that this configuration will take priority over the earlier files like 01- or 50-.

To get the gateway address (route), you can use the following command:

kc@kchomelab:~$ ip route | grep default
default via 192.168.0.1 dev wlo1 proto dhcp src 192.168.0.20 metric 600

/etc/netplan/99-static-ip.yaml

network:
  version: 2
  renderer: NetworkManager
  # ethernets: # for wired connection, use 'ethernets'
  wifis: # for wireless connection, use 'wifis'
    wlo1: # use the actual interface name
      dhcp4: no # this overrides the 'yes' in the 50-cloud-init file
      dhcp6: no # this overrides the 'yes' in the 50-cloud-init file
      addresses: # static IP
        - 192.168.0.20/24
      routes:
        - to: default
          via: 192.168.0.1
      nameservers:
        addresses: [8.8.8.8, 8.8.4.4, 1.1.1.1]
      access-points: # for wireless connection only
        "kc_5G":
          password: <wireless-password>

nameservers must be set as computer only speak in IP address format, but we use domain names to access websites, so in order to translate domain names to IP addresses, we need to use nameservers.
- 8.8.8.8 = Google Public DNS
- 8.8.4.4 = Google Secondary Public DNS
- 1.1.1.1 = Cloudflare Public DNS

Step 3: Apply the netplan configuration

Try the configuration first to se if there are any errors:

kc@kchomelab:~$ sudo netplan try

** (process:13133): WARNING **: 14:01:57.841: Permissions for /etc/netplan/01-network-manager-all.yaml are too open. Netplan configuration should NOT be accessible by others.

** (process:13133): WARNING **: 14:01:57.842: Permissions for /etc/netplan/99-static-ip.yaml are too open. Netplan configuration should NOT be accessible by others.

Fix the "Permissions are too open" warning by changing the file permissions.

sudo chmod 600 /etc/netplan/01-network-manager-all.yaml
sudo chmod 600 /etc/netplan/99-static-ip.yaml

If everything looks good, apply the configuration:

kc@kchomelab:~$ sudo netplan try
Do you want to keep these settings?


Press ENTER before the timeout to accept the new configuration


Changes will revert in 106 seconds
Configuration accepted.

kc@kchomelab:~$ sudo netplan apply

Step 4: Check Static IP setup successfully?

Facing issues

If you still see dynamic keyword from ip addr or proto dhcp keyword from ip route command. You might need to do some configuration.

First, disable cloud-init network management. This is dealing with 50-cloud-init.yaml to avoid conflicts.

echo "network: {config: disabled}" | sudo tee /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

Next, if you have multiple files in /etc/netplan, delete or rename the ones you aren't using, for my case, I create a backup folder and move those files into backup folder to avoid merging conflicts.

mkdir backup
mv 50-cloud-init.yaml 90-NM-*.yaml backup/

Remove the old dynamic lease and apply the netplan configuration.

sudo ip addr flush dev <interface-name>
sudo netplan apply

You can check whether the static IP is setup successfully by using two commands:

ip addr
ip route

For ip addr command, you will notice the dynamic keyword is gone.

kc@kchomelab:/etc/netplan$ ip addr show wlo1
3: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether a0:29:42:00:3c:78 brd ff:ff:ff:ff:ff:ff
    altname wlp0s20f3
    inet 192.168.0.20/24 brd 192.168.0.255 scope global noprefixroute wlo1
       valid_lft forever preferred_lft forever
    inet6 2001:e68:545b:1e09:435:c1ff:b38f:d374/64 scope global temporary dynamic 
       valid_lft 206237sec preferred_lft 86014sec
    inet6 2001:e68:545b:1e09:a229:42ff:fe00:3c78/64 scope global dynamic mngtmpaddr 
       valid_lft 206237sec preferred_lft 119837sec
    inet6 fe80::a229:42ff:fe00:3c78/64 scope link 
       valid_lft forever preferred_lft forever

For ip route command, you will notice proto static.

kc@kchomelab:/etc/netplan$ ip route | grep default
default via 192.168.0.1 dev wlo1 proto static metric 600

One final test to ensure the internet routing and DNS are working correctly:

kc@kchomelab:~$ ping -c 3 google.com
PING google.com (2404:6800:4001:804::200e) 56 data bytes
64 bytes from pnkula-ah-in-x0e.1e100.net (2404:6800:4001:804::200e): icmp_seq=1 ttl=120 time=10.9 ms
64 bytes from pnkula-ah-in-x0e.1e100.net (2404:6800:4001:804::200e): icmp_seq=2 ttl=120 time=13.4 ms
64 bytes from pnkula-ah-in-x0e.1e100.net (2404:6800:4001:804::200e): icmp_seq=3 ttl=120 time=12.2 ms

--- google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 10.868/12.135/13.378/1.024 ms