Set custom DNS servers on Ubuntu 18.04 or 20.04

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Today, I’ll show you three methods to set custom DNS servers on Ubuntu, including instructions to reset your connection back to defaults if you need to. Below each guide is a video version for further explanation.

Contents

Set DNS servers with Network Manager

This is the easiest way to set custom DNS servers on Ubuntu and the preferred method because you’re not messing with any system files, which can lead to trouble if you’re not Linux savvy. Please note that each version of the Ubuntu GUI is slightly different so you may need to improvise. The screenshots below are from Ubuntu 20.04 LTS.

  1. Click the Network icon top-right of your screen, then Wired Connected -> Wired settings (Or Wi-Fi Adapter)
    Click network icon, then Settings
  2. Click the Gear icon under the Wired or Wi-Fi heading
    Click the Gear icon
  3. Click the IPv4 tab and enter your custom DNS server IP addresses, separated by a comma, then toggle the Automatic button and click Apply
    Enter your custom DNS servers addresses, toggle Automatic
  4. (Optional) Click the IPv6 tab and enter your custom DNS server IP addresses, separated by a comma, then toggle the Automatic button and click Apply. Note: If you don’t have IPv6 IP addresses you can disable IPv6 altogether with no negative effect: IPv6 Method -> Disable -> Apply
    Enter IPv6 addresses, toggle Automatic
  5. Toggle the LAN/Wi-Fi connection off and on
    Toggle your connection off and on
  6. Open up a Terminal window and enter the following command: systemd-resolve --status, then hit the END key on your keyboard (or just keep hitting Enter till you get to the last line). You should see your Ethernet/W-Fi interface listed with the DNS servers you set earlier, mine is Link 2 (enp0s3):
    Check you DNS servers
    #If you don’t see your DNS servers listed, please make sure you followed all the steps in this guide. If you still have trouble, drop a comment further below.

Video: Set DNS servers with Network Manager

Set DNS servers with Netplan, Network Manager and static IP

Note* As of 18/05/2020 Network Manager doesn’t respect the Netplan option nameservers: addresses [8.8.8.8,8.8.4.4] option even when you specify dhcp4-overrides: use-dns: false, it still uses (and give priority to) the default DHCP DNS servers. This renders any custom DNS servers redundant. The only way around this AFAIK is to specify the Ethernet connection as static. Please comment or email me if you have found otherwise.

  1. Open up a Terminal window and enter: ip a to list your current Ethernet/W-Fi connection details. Find your wired/Wi-Fi link name, mine is enp0s3 and just under that, you’ll see the IP address and netmask, mine is inet 192.168.1.114/24. Enter ip route show to reveal your default gateway, mine is default via 192.168.1.1. Keep this window open or write down the IP, netmask and default gateway.
    Result of ip a command
  2. Open File Manager and navigate to /etc/netplan, right-click and choose Open in Terminal. Enter the dir command, then select and copy the *.yaml file name to clipboard. Enter sudo nano [filename].yaml to open your Netplan config file (paste the file name from clipboard).
    Network Manager YAML file
  3. Copy and paste the code below and change everything in CAPS to your own. Indenting is critical for YAML so if you copy/paste be sure to keep the formatting. If you do lose formatting, make sure you indent using the space bar not TAB otherwise YAML will throw an error.
    network:
        version: 2
        renderer: NetworkManager
        ethernets:
           [DEVICE_NAME]:
              dhcp4: false
              addresses: [IP_ADDRESS/NETMASK]
              gateway4: GATEWAY_IP
              nameservers:
                 addresses: [NAMESERVER_1, NAMESERVER_2]

    My details are as follows:
    network:
        version: 2
        renderer: NetworkManager
        ethernets:
           enp0s3:
              dhcp4: false
              addresses: [192.168.1.114/24]
              gateway4: 192.168.1.1
              nameservers:
                 addresses: [8.8.8.8, 8.8.4.4]

    Then save ctrl + o, ENTER and exit nano ctrl + x. Now apply the changes sudo netplan apply. If you get a warning you may have used TAB instead of space bar, or you have a syntax error, open the YAML file up and double check everything. If you get nothing but a new line on command prompt, you’re good to go.
  4. Once your YAML code has been applied without errors, enter systemd-resolve --status and confirm you’re using specified DNS servers:
    Check you DNS servers

Video: Set DNS servers with Netplan, Network Manager and static IP

Set custom DNS using Netplan and networkd

Using this method you’ll lose the Network Manager GUI and network icon, so only use if necessary (I recommend methods 1 or 2).

  1. Open File Manager and navigate to /etc/netplan, right-click and choose Open in Terminal. Enter the dir command, then select and copy the *.yaml file name to clipboard. Enter sudo nano [filename].yaml to open your Netplan config file (paste the file name from clipboard):
    Network Manager YAML file
  2. Copy and paste the code below replacing CAPS with your values (take note the renderer is changed to networkd), but please make sure you indent using the space bar not TAB otherwise YAML will throw an error:
    network:
        version: 2
        renderer: networkd
        ethernets:
           [DEVICE_NAME]:
              dhcp4: true
              nameservers:
                 addresses: [NAMESERVER_1, NAMESERVER_2]

    Mine looks like this:
    network:
        version: 2
        renderer: networkd
        ethernets:
           enp0s3:
              dhcp4: true
              nameservers:
                 addresses: [8.8.8.8, 8.8.4.4]

    Then save ctrl + o, ENTER and exit nano ctrl + x, then apply changes: sudo netplan apply. If you get a warning, it’s likely you’ve used TAB instead of space bar or you have a syntax error, open the YAML file up and double check everything. If you get nothing but a new line on command prompt, you’re good to go.
  3. Once your YAML code has been applied without errors, enter systemd-resolve --status to confirm you’re using specified DNS servers:
    Check you DNS servers

Video: Set custom DNS using Netplan and networkd

Watch the YouTube video: Video: Set custom DNS using Netplan and networkd

Reset your Ethernet connection back to defaults

If you’ve run into trouble or just want to reset your connection back to defaults, follow these instructions (for methods 2 and 3 only).

  1. Open File Manager and navigate to /etc/netplan, right-click and choose Open in Terminal. Enter the dir command, then select and copy the *.yaml file name to clipboard. Enter sudo nano [filename].yaml to open your Netplan config file (paste the file name from clipboard).
  2. Remove everything, then copy/paste the following code, or enter it manually:
    network:
        version: 2
        renderer: NetworkManager

    Then save ctrl + o, ENTER and exit nano ctrl + x, then apply changes: sudo netplan apply. If you get a warning, it’s likely you’ve used TAB instead of space bar or you have a syntax error, open the YAML file up and double check everything. If you get nothing but a new line on command prompt, you’re good to go.

Video: Reset your Ethernet connection back to defaults

Conclusion

You should now have custom DNS servers on your Ubuntu PC. If you ran into any issues, hit me up in the comments or socials/email.

See Also

Further Reading

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Categories Ubuntu

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