Network Manager needs restarting from sleep

[Cefn]

Each time my laptop is suspended and resumed, Network Manager seems unable to bring up Wifi.

Calling...

sudo service network-manager restart

...resolves the problem.

I therefore placed the attached file at...

/lib/systemd/system-sleep/network-manager

...which provides a workaround for the problem. However, there must be some kind of underlying bug in network-manager which requires it to be restarted after every suspend/resume cycle.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: network-manager 1.2.6-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-66.87-generic 4.4.44
Uname: Linux 4.4.0-66-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
CurrentDesktop: LXDE
Date: Tue Mar 28 10:21:35 2017
EcryptfsInUse: Yes
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
IpRoute:
 default via 192.168.1.1 dev wlp1s0 proto static metric 600
 172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
 192.168.1.0/24 dev wlp1s0 proto kernel scope link src 192.168.1.203 metric 600
JournalErrors:
 Error: command ['journalctl', '-b', '--priority=warning', '--lines=1000'] failed with exit code 1: Hint: You are currently not seeing messages from other users and the system.
       Users in the 'systemd-journal' group can see all messages. Pass -q to
       turn off this notice.
 No journal files were opened due to insufficient permissions.
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
WifiSyslog:

nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
 docker0 bridge connected /org/freedesktop/NetworkManager/Devices/1 docker0 ac7e4d66-b979-41de-b4b2-6f7c5dffc232 /org/freedesktop/NetworkManager/ActiveConnection/0
 wlp1s0 wifi connected /org/freedesktop/NetworkManager/Devices/0 Kitchen 2 937ae07a-fb47-46ac-91a4-0fe200203a95 /org/freedesktop/NetworkManager/ActiveConnection/1
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/2 -- -- --
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.2.6 connected started full enabled enabled enabled enabled enabled

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[gutschke (markus+launchpad)]

Please note that bug 1666318 has relevant information. It appears that editing

/etc/NetworkManager/NetworkManager.conf

and removing "dns=dnsmasq" makes the problem go away.

So, this could be a bug in either network manager or in dnsmasq

[Creak (romain-failliot)]

And the bug #1676081 also has relevant information toward VPN connections:

> Side effect of the workaround: it closes the VPN connection if there was one before.

[Vikas (f2008700)]

Noticing the same on Ubuntu 22.04.