[Bug 1816530] Re: DNS servers are not being set in the system correctly when you upgrade from 16.04 to 18.04

[Moshe Caspi]

True, the upgrade completed successfully but without DNS which is
reasonable because I don't think that a user needs a network connection
after the files were downloaded. But I experience Wi-Fi disconnects once
in a while.

Anyway, I tried to figure out what might be the reason for the absent of
DNS. During the upgrade I choosed to keep my files when asked to keep or
change to the distro one's. I tried to remember which files I kept and
checked for network related files and I found that my
NetworkManager.conf was different from the distro file which was copied
to /etc/NetworkManager during the upgrade.

My old file:

[main]
plugins=ifupdown,keyfile,ofono
dns=dnsmasq

no-auto-default=aa:bb:cc:dd:ee:ff,

[ifupdown]
managed=false

The distro file:

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false

[device]
wifi.scan-rand-mac-address=no

So, I decided to use the distro file instead my old file and now the DNS
works.

What I see now in syslog which might be related and I don't see when I
used 8.8.8.8 as a workaround is this:

Oct 10 09:47:58 systemd-resolved[335]: Using degraded feature set (UDP) for DNS server a.b.c.d.
Oct 10 09:57:05 systemd-resolved[335]: Grace period over, resuming full feature set (UDP+EDNS0) for DNS server a.b.c.d.
Oct 10 10:06:35 systemd-resolved[335]:Using degraded feature set (UDP) for DNS server a.b.c.d.


On Tue, 08 Oct 2019 20:06:40 -0000
Dan Streetman <dan.streetman at canonical.com> wrote:

> > During the upgrade which was done using Wi-Fi, the connection went
> down but it was after the download completed so the upgrade ended.
> 
> sorry, it's not clear to me, are you saying the upgrade completed
> successfully?
> 
> And do you mean that currently, your dns does not work?
> 
> -- 
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1816530
> 
> Title:
>   DNS servers are not being set in the system correctly when you upgrade
>   from 16.04 to 18.04
> 
> Status in resolvconf package in Ubuntu:
>   Invalid
> 
> Bug description:
>   I upgraded my 16.04 to 18.04 before the official release. After the
>   upgrade I noticed that I don't have internet access. The wired network
>   and the wifi settings looked good, but the internet didn't work. After
>   the login the system always switched itself into airplane mode. I
>   tethered the network via USB and Bluetooth by my mobile but they also
>   didn't work.
> 
>   I found a useful answer from @andrew-woodhead666:
>   https://answers.launchpad.net/ubuntu/+question/665374
> 
>   it seems this bug is still not fixed for the upgraded dists in the main release and affects a few dozens of ubuntu users.
>   https://askubuntu.com/questions/1021884/no-internet-after-upgrade-from-16-04-to-18-04
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/1816530/+subscriptions

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to resolvconf in Ubuntu.
https://bugs.launchpad.net/bugs/1816530

Title:
  DNS servers are not being set in the system correctly when you upgrade
  from 16.04 to 18.04

Status in resolvconf package in Ubuntu:
  Invalid

Bug description:
  I upgraded my 16.04 to 18.04 before the official release. After the
  upgrade I noticed that I don't have internet access. The wired network
  and the wifi settings looked good, but the internet didn't work. After
  the login the system always switched itself into airplane mode. I
  tethered the network via USB and Bluetooth by my mobile but they also
  didn't work.

  I found a useful answer from @andrew-woodhead666:
  https://answers.launchpad.net/ubuntu/+question/665374

  it seems this bug is still not fixed for the upgraded dists in the main release and affects a few dozens of ubuntu users.
  https://askubuntu.com/questions/1021884/no-internet-after-upgrade-from-16-04-to-18-04

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/1816530/+subscriptions