Local servers not reachable as NetworkManager adds spurious nameserver 127.0.1.1 to resolv.conf

[Karl Kastner]

Since upgrade to 17.04/17.10 I cannot reach any server within my university domain over LAN:

From within the university network:
ping webmail.wur.nl
ping: webmail.wur.nl: Name or service not known

From outside:
ping webmail.wur.nl
PING webmail.wur.nl (137.224.252.102) 56(84) bytes of data.

This is caused by the entry of the local host as nameserver in resolf.conf as "nameserver 127.0.1.1".

When this line is manually removed the server is reached. However, NetworkManager persistently restores the line to /etc/resolf.conf. This can be avoided by stopping NetworkManager, adding dns=none to the [main] section to /etc/NetworkManager/NetworkManager.conf and then restarting NetworkManager.

NetworkManager should not add the line nameserver 127.0.1.1 to resolv.conf on default, as this almost surely causes problems.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: network-manager 1.8.4-1ubuntu3.1
ProcVersionSignature: Ubuntu 4.13.0-29.32-generic 4.13.13
Uname: Linux 4.13.0-29-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.7
Architecture: amd64
CurrentDesktop: GNOME
Date: Tue Jan 30 15:18:38 2018
InstallationDate: Installed on 2015-11-05 (817 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
IpRoute:
 default via 10.75.15.254 dev eth0 proto static metric 100
 10.75.0.0/20 dev eth0 proto kernel scope link src 10.75.0.58 metric 100
 169.254.0.0/16 dev eth0 scope link metric 1000
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=false
 WWANEnabled=true
SourcePackage: network-manager
UpgradeStatus: Upgraded to artful on 2018-01-16 (14 days ago)
mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2018-01-30T15:14:52.823904
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
 eth0 ethernet connected /org/freedesktop/NetworkManager/Devices/2 Wired connection 1 8bdd2177-0b8e-3365-82d1-1d5ea4cc3bc2 /org/freedesktop/NetworkManager/ActiveConnection/2
 wlan0 wifi unavailable /org/freedesktop/NetworkManager/Devices/3 -- -- --
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/1 -- -- --
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.8.4 connected started full enabled enabled disabled enabled enabled