I have been affected by this one for a time now on a 18.04 LTS install on a laptop with both wired and wireless ethernet. Not a fresh install, but one that had been upgraded from earlier releases.
I have both Wireless and wired ethernet configured. NetworkManager is taking care of network IP address assignment, which is done dynamically on both cases through DHCP from the AP/router. Every now and then, I get both network interfaces with no IP address assigned whatsoever. It may happen after resuming from suspend (laptop being powered down from hours to days) or while actively using the laptop. In all cases it seems NetworkManager service is still running and "dhclient" processes are up and running for the interfaces. For the latest time this has occured to me: """ # service NetworkManager status ● NetworkManager.service - Network Manager Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled) Active: active (running) since Fri 2018-11-16 21:31:31 CET; 4 days ago Docs: man:NetworkManager(8) Main PID: 845 (NetworkManager) Tasks: 5 (limit: 4915) CGroup: /system.slice/NetworkManager.service ├─ 845 /usr/sbin/NetworkManager --no-daemon ├─12154 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /run/dhclient-wlp3s0.pid -lf /var/lib/NetworkManager/dhclient-cef3df46-08a4-4e76-b0d8-3a2c21cd504e-wlp3s0.lease -cf /var/lib/NetworkManager/dhclient-wl └─23839 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /run/dhclient-enp0s25.pid -lf /var/lib/NetworkManager/dhclient-7d46e9cc-ee9c-366d-a025-73d355f9d046-enp0s25.lease -cf /var/lib/NetworkManager/dhclient- # ps -efa | grep Netwo root 845 1 0 nov16 ? 00:00:20 /usr/sbin/NetworkManager --no-daemon root 1207 2521 0 14:13 pts/1 00:00:00 grep --color=auto Netwo root 12154 845 0 nov20 ? 00:00:00 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /run/dhclient-wlp3s0.pid -lf /var/lib/NetworkManager/dhclient-cef3df46-08a4-4e76-b0d8-3a2c21cd504e-wlp3s0.lease -cf /var/lib/NetworkManager/dhclient-wlp3s0.conf wlp3s0 root 23839 845 0 nov20 ? 00:00:00 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /run/dhclient-enp0s25.pid -lf /var/lib/NetworkManager/dhclient-7d46e9cc-ee9c-366d-a025-73d355f9d046-enp0s25.lease -cf /var/lib/NetworkManager/dhclient-enp0s25.conf enp0s25 """ For me, getting IP addresses assigned again to interfaces is as easy as running "service NetworkManager restart". Last significant logs in /var/log/syslog prior to losing connectivity (IP address) on both network interfaces (wired "enp0s25" and wireless "wlp3s0") are as below: """ #### Wireless interface goes "timed out" Nov 21 12:13:40 laptop NetworkManager[845]: <info> [1542798820.8236] connectivity: (wlp3s0) timed out Nov 21 12:13:40 laptop avahi-daemon[841]: Withdrawing address record for 192.168.1.17 on wlp3s0. Nov 21 12:13:40 laptop avahi-daemon[841]: Leaving mDNS multicast group on interface wlp3s0.IPv4 with address 192.168.1.17. Nov 21 12:13:40 laptop avahi-daemon[841]: Interface wlp3s0.IPv4 no longer relevant for mDNS. #### And exactly 20 minutes later so does the wired interface... Nov 21 12:33:40 laptop NetworkManager[845]: <info> [1542800020.8236] connectivity: (enp0s25) timed out Nov 21 12:33:40 laptop NetworkManager[845]: <info> [1542800020.8237] manager: NetworkManager state is now CONNECTED_SITE Nov 21 12:33:40 laptop avahi-daemon[841]: Withdrawing address record for 192.168.1.19 on enp0s25. Nov 21 12:33:40 laptop systemd[1]: Starting Network Manager Script Dispatcher Service... Nov 21 12:33:40 laptop avahi-daemon[841]: Leaving mDNS multicast group on interface enp0s25.IPv4 with address 192.168.1.19. Nov 21 12:33:40 laptop gsd-sharing[1976]: Failed to StopUnit service: GDBus.Error:org.freedesktop.systemd1.NoSuchUnit: Unit gnome-user-share-webdav.service not loaded. Nov 21 12:33:40 laptop avahi-daemon[841]: Interface enp0s25.IPv4 no longer relevant for mDNS. Nov 21 12:33:40 laptop gsd-sharing[1976]: Failed to StopUnit service: GDBus.Error:org.freedesktop.systemd1.NoSuchUnit: Unit rygel.service not loaded. Nov 21 12:33:40 laptop dbus-daemon[812]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service' requested by ':1.9' (uid=0 pid=845 comm="/usr/sbin/NetworkManager --no-daemon " label="unconfined") Nov 21 12:33:40 laptop gsd-sharing[1976]: Failed to StopUnit service: GDBus.Error:org.freedesktop.systemd1.NoSuchUnit: Unit gnome-remote-desktop.service not loaded. Nov 21 12:33:40 laptop dbus-daemon[812]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher' Nov 21 12:33:40 laptop systemd[1]: Started Network Manager Script Dispatcher Service. Nov 21 12:33:40 laptop nm-dispatcher: req:1 'connectivity-change': new request (1 scripts) Nov 21 12:33:40 laptop nm-dispatcher: req:1 'connectivity-change': start running ordered scripts... Nov 21 12:33:40 laptop nm-dispatcher: req:2 'connectivity-change': new request (1 scripts) Nov 21 12:33:40 laptop nm-dispatcher: req:2 'connectivity-change': start running ordered scripts... Nov 21 12:34:00 laptop whoopsie[1357]: [12:34:00] Cannot reach: https://daisy.ubuntu.com Nov 21 12:34:00 laptop whoopsie[1357]: [12:34:00] offline """ It can't be a coincidence both network devices lose the IP addresses due to some "timed out" event exactly 20 minutes apart. As the event comes from NetworkManager, so must be the bug causing the observed behavior. Please check if possible to strengthen NetworkManager in the current and upcoming releases. Mine being now: """ # cat /etc/os-release NAME="Ubuntu" VERSION="18.04.1 LTS (Bionic Beaver)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 18.04.1 LTS" VERSION_ID="18.04" HOME_URL="https://www.ubuntu.com/" SUPPORT_URL="https://help.ubuntu.com/" BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/" PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy" VERSION_CODENAME=bionic UBUNTU_CODENAME=bionic """ -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1771749 Title: Ethernet connection lost after few minutes since starting Status in linux package in Ubuntu: Confirmed Status in network-manager package in Ubuntu: Confirmed Bug description: This is the same bug I notified at Bug #1770848 but with a more precise selection of (what I think it is) the package affected and a better description. I made a few days ago a fresh install of the Kubuntu 18.04 LTS and it is most everything Ok, but -I think that- the network-manager has a problem. In the last LTS version, Kubuntu 16.04, nor in any Linux version if I remember well, I never lost connection through Ethernet (the only Internet connection with our desktop PC), but the Bionic Beaver loses the connection every now and then, perhaps within few minutes or hours, but several times per day. When the connection is lost, I note that it disappears any info even mention to any network into the network window and the network manager icon becomes red color. Not matter if I unplug and then plug the ethernet cable again, the ethernet connection is not longer detected and only restarting the PC makes the connection to work again. Incidentally, I also have noticed with this version of Kubuntu 18.04 that in my laptop there is also now a similar problem with the scanner: If I plug it in some USB port of the laptop once Kubuntu 18.04 is already running, it's not detected by Xsane. I have to plug it in before than pressing the power button or at the time of starting the OS, for the scanner to be detected by the scanning program (and then only works with Xsane, not if I use Simple Scan or Skanlite, even when it works under Xsane), as I said in the Bug #1771525 and, evenly, if I unplug the scanner cable from the USB port it is not detected anymore when plugging it again, and only restarting the laptop makes it to be detected. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: network-manager 1.10.6-2ubuntu1 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 CurrentDesktop: KDE Date: Thu May 17 08:24:23 2018 IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback InstallationDate: Installed on 2018-05-11 (5 days ago) InstallationMedia: Kubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) IpRoute: default via 192.168.1.1 dev enp0s7 proto static metric 100 169.254.0.0/16 dev enp0s7 scope link metric 1000 192.168.1.0/24 dev enp0s7 proto kernel scope link src 192.168.1.3 metric 100 IwConfig: enp0s7 no wireless extensions. lo no wireless extensions. NetworkManager.state: [main] NetworkingEnabled=true WirelessEnabled=true WWANEnabled=true PciNetwork: RfKill: SourcePackage: network-manager UpgradeStatus: No upgrade log present (probably fresh install) nmcli-con: NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT AUTOCONNECT-PRIORITY READONLY DBUS-PATH ACTIVE DEVICE STATE ACTIVE-PATH SLAVE Conexión cableada 1 1cc37db8-0db8-3887-acf2-59fbbcd0cb1c ethernet 1526538083 jue 17 may 2018 08:21:23 CEST yes 4294967196 no /org/freedesktop/NetworkManager/Settings/1 yes enp0s7 activated /org/freedesktop/NetworkManager/ActiveConnection/1 -- nmcli-dev: DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH enp0s7 ethernet connected /org/freedesktop/NetworkManager/Devices/2 Conexión cableada 1 1cc37db8-0db8-3887-acf2-59fbbcd0cb1c /org/freedesktop/NetworkManager/ActiveConnection/1 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/1 -- -- -- nmcli-nm: RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN running 1.10.6 connected started full enabled enabled enabled enabled enabled --- ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: nosotros 1116 F.... pulseaudio /dev/snd/controlC1: nosotros 1116 F.... pulseaudio CurrentDesktop: KDE DistroRelease: Ubuntu 18.04 HibernationDevice: RESUME=UUID=bb1531db-e7c0-48eb-a5b7-5afe3df47ba3 IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback InstallationDate: Installed on 2018-05-11 (6 days ago) InstallationMedia: Kubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) IpRoute: default via 192.168.1.1 dev enp0s7 proto static metric 100 169.254.0.0/16 dev enp0s7 scope link metric 1000 192.168.1.0/24 dev enp0s7 proto kernel scope link src 192.168.1.3 metric 100 IwConfig: enp0s7 no wireless extensions. lo no wireless extensions. Lsusb: Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 002: ID 04fc:0005 Sunplus Technology Co., Ltd USB OpticalWheel Mouse Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M. NetworkManager.state: [main] NetworkingEnabled=true WirelessEnabled=true WWANEnabled=true Package: network-manager 1.10.6-2ubuntu1 PackageArchitecture: amd64 PciNetwork: ProcFB: 0 radeondrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-20-generic root=UUID=d1d6ad93-b21c-43cd-8410-782414a5f935 ro quiet splash vt.handoff=1 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 RelatedPackageVersions: linux-restricted-modules-4.15.0-20-generic N/A linux-backports-modules-4.15.0-20-generic N/A linux-firmware 1.173 RfKill: Tags: bionic Uname: Linux 4.15.0-20-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True dmi.bios.date: 07/17/2009 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: P1.50 dmi.board.name: N68-S dmi.board.vendor: ASRock dmi.chassis.asset.tag: To Be Filled By O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: To Be Filled By O.E.M. dmi.chassis.version: To Be Filled By O.E.M. dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP1.50:bd07/17/2009:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnN68-S:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.: dmi.product.family: To Be Filled By O.E.M. dmi.product.name: To Be Filled By O.E.M. dmi.product.version: To Be Filled By O.E.M. dmi.sys.vendor: To Be Filled By O.E.M. nmcli-con: NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT AUTOCONNECT-PRIORITY READONLY DBUS-PATH ACTIVE DEVICE STATE ACTIVE-PATH SLAVE Conexión cableada 1 1cc37db8-0db8-3887-acf2-59fbbcd0cb1c ethernet 1526562681 jue 17 may 2018 15:11:21 CEST yes 4294967196 no /org/freedesktop/NetworkManager/Settings/1 yes enp0s7 activated /org/freedesktop/NetworkManager/ActiveConnection/1 -- nmcli-dev: DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH enp0s7 ethernet connected /org/freedesktop/NetworkManager/Devices/2 Conexión cableada 1 1cc37db8-0db8-3887-acf2-59fbbcd0cb1c /org/freedesktop/NetworkManager/ActiveConnection/1 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/1 -- -- -- nmcli-nm: RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN running 1.10.6 connected started full enabled enabled enabled enabled enabled To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1771749/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp