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stackinator
Asked: 2018-12-03 19:09:08 +0800 CST

18.04 - does it force netplan or can I still use resolved.conf?

  • 772

I kept getting timeout errors on 18.04 Bionic Beaver, until I switched to OpenDNS using these commands 

sudo rm -f /etc/resolv.conf 
sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf 
sudo nano /etc/systemd/resolved.conf
# with body 
nameserver 208.67.222.222

Should I really be doing this OpenDNS configuration with Netplan? I tried the following but it doesn't work.

# Create a netplan file
sudo vi /etc/netplan/50-cloud-init.yaml

.

# Put this in the body
nameservers: 
    addresses: [208.67.222.222, 208.67.220.220]

I also tried this syntax in the body to no avail, but maybe it because I'm on wifi and I called out 'ethernet'??? wlo1 is my wifi logical name when I sudo lshw -C network.

network:
  ethernet:
    wlo1:
      nameservers:
        addresses: [208.67.222.222, 208.67.220.220]
networking network-manager dns 18.04 netplan

2 Answers

  1. Best Answer

    You first have to make a decision to use NetworkManager or systemd-networkd. If you connect wi-fi to various wireless networks, then NetworkManager is probably the better choice. systemd-networkd is best used in servers, where the configuration doesn't change much. See https://netplan.io/examples.

    /etc/netplan .yaml example to enable NetworkManager...

    network:
  version: 2
  renderer: NetworkManager

    In terminal...

    sudo netplan generate # generate config files

    sudo netplan apply # apply the new config

    reboot # reboot to confirm network operation

    • 4

  2. Another option is systemd-networkd.service, instead of NetworkManager.service.

    Background story

    I was having problems with NetworkManager when after changing network settings a couple of times the DNS would fail.

    I noticed that systemd-resolved.service is supposed to work with both network-manager and systemd-network.

    But systemd-networkd is actually part of the systemd family of software. So (I thought maybe) it will communicate better with systemd-networkd than NetworkManager. It tried it and it did seem better.

    How to set up systemd-networkd

    Set up /etc/systemd/network/10-enp2s0.network where enp2s0 is the name of your interface as seen with ifconfig. It might be eth0. Here is a simple example of DHCP with DNS override. Note the DNS= directive can be used multiple times.

    [Match]
MACAddress=1c:dd:dd:dd:dd:dd

[Network]
DHCP=yes
DNS=208.67.222.222
DNS=208.67.220.220

    The [Network] section for a fixed address.

    [Network]
Address=192.168.1.172/24
Gateway=192.168.1.1
DNS=208.67.222.222
DNS=208.67.220.220

    More examples

    Test it out - 

    systemctl stop NetworkManager.service
systemctl start systemd-networkd.service
systemctl restart systemd-resolved.service

    On my system with systemd-resolved running, the resolv.conf file is a link - 

    /etc/resolv.conf -> ../run/systemd/resolve/stub-resolv.conf

    If the link is not replaced automatically during the restart, you might want to link it manually and restart systemd-resolved again.

    If its working as hoped than set their boot time startup behaviour - 

    systemctl disable NetworkManager.service
systemctl enable systemd-networkd.service

    Blame

    There are always two sides to an interface.

    • 2