15

I've decided systemd-resolved is irretrievably broken garbage and I'd like to replace. I've got my own local DNS server at 192.168.1.2 I'd like. I'd also like to connect to a VPN with NetExtender that gives me a DNS server for a .local domain. I would like these two things to work together, what can I do?

gct
  • 251

3 Answers3

6

The answer by Gannet is incorrect. If you want to use plain ifupdown like in earlier releases, without netplan or NetworkManager (e.g. on a server), with dhcp, you need to do this:

systemctl disable systemd-resolved.service
systemctl stop systemd-resolved.service

check if resolv.conf is pointing to resolvconf


ls -la /etc/resolv.conf


lrwxrwxrwx 1 root root 27 May  7 16:15 /etc/resolv.conf -> /run/resolvconf/resolv.conf


if not, delete /etc/resolv.conf and symlink it like this:


rm /etc/resolv.conf
ln -s /run/resolvconf/resolv.conf /etc/resolv.conf


this will remove the resolved stub resolver entry from resolv.conf


resolvconf -d systemd-resolved


fix dhclient scripts


chmod -x /etc/dhcp/dhclient-enter-hooks.d/resolved
chmod +x /etc/dhcp/dhclient-enter-hooks.d/resolvconf


on my machine just chmod -x wasn't enough, I had to move the resolved script somewhere else


mv /etc/dhcp/dhclient-enter-hooks.d/resolved ~


ifdown/ifup your interface to regenerate resolv.conf (or systemctl restart ifup@eth0)


ifdown eth0; ifup eth0


check /etc/resolv.conf has the right settings
jjakob
  • 69
3

You can always disable your systemd-resolved by

systemctl disable systemd-resolved.service

command. And run:

sudo rm /etc/resolv.conf && sudo ln -s /run/systemd/resolve/stub-resolv.conf /etc/resolv.conf

to use /etc/resolv.conf config as it was earlier in previous ubuntu versions.

Gannet
  • 521
-1

Both answers can lead to issues with VPN. Also, if it's desired to keep NetworkManager, the following can be done:

Unlink resolvconf if this is linked to resolvectl:

ls -lah $(which resolvconf)

If resolveconf is linked to resolvectl, like the following:

/usr/local/bin/resolvconf -> /usr/bin/resolvectl

We need to unlink it:

sudo unlink /usr/local/bin/resolvconf

Now, install resolvconf because most VPN uses it:

sudo apt-get install resolvconf

set dns=none to [main] section in /etc/NetworkManager/NetworkManager.conf:

[main]
...
dns=none

Now, we have two options here:

  • Manually set DNSes system-wide
  • Use resolvconf to set DNS:

Manually set DNSes system-wide

Place desired DNS servers as nameserver in /etc/resolv.conf:

nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 1.1.1.1

Use resolvconf to set DNS

This is preferred way if you're using a VPN with specific DNS servers configured through it

sudo ln -sfn /run/resolvconf/resolv.conf /etc/resolv.conf
meetnick
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  • 3
  • 17
  • I followed your guide and now I have no internet. Any help would be appreciated. Thanks! – Alex Nov 02 '22 at 01:49
  • I made a new post about this. Feel free to comment there. Thanks https://askubuntu.com/questions/1438645/modified-dns-settings-to-fix-wireguard-but-disabled-internet – Alex Nov 02 '22 at 02:01
  • @Alex could you please post modified files content?
    • ls -lah $(which resolvconf)
    • /etc/NetworkManager/NetworkManager.conf
    • /etc/resolv.conf
     – meetnick Jan 11 '23 at 15:44