Perhaps this can help: The symptoms I experience started sometime during the past year after an update (sudo apt update && sudo apt upgrade && sudo apt autoremove) are that some indefinite time (usually less than ½ hour) after I log on, the network disconnects without warning or error. Clicking on the up/down arrows of the indicator plugin and selecting the interface reconnects; however, I recently discovered that if, as soon as I log on, I select "Disconnect" and then select the adapter to reconnect, my session will be fine until I log out and back in again. So perhaps the bug is not with network-manager, samba or ifupdown, but with the logon process(es). My version is 18.04 and I'm using LiteDM GTK+. I haven't the faintest idea where to look for a cause that might be related to the logon process(s), but none of the very many "solutions" offered on various web pages I found on the problem have fixed it for me.
One other unexpected thing I've noticed is that in editing Ethernet connections (I don't used wireless enough to have noticed a problem), I can't edit (or delete) the one the system creates without first adding another (even if it's the same, e.g., enp2s0, with the same settings) and switching to it; however, after I did that the first time, and deleted the system's entry ("Wired connection 1", I think it was called), at some point the system added another entry, identical in every way to the one I had added, but called "Ifupdown (enp2s0)" and connects to that when I log on, not to the one I created (which I have since deleted, but the original problem still occurs, and disconnecting and reconnecting still prevents the random disconnect). All of this applies to 2 other machines, also running up-to-date xubuntu 18.04, although on one of the other machines, the adapter is enp4s25. It also occurs with xubuntu and xfce sessions. I suspect the difficutly in finding the cause(s) is in part due to the confusing way samba/network settings are stored, with the same setting sometimes stored in different locations, entered via GUI or command line or both, possibly leading to conflicts. I have spent many hours on this problem, and have only the above work- around, not a fix. Even though this problem has been around longer than 18.04, since 18.04, samba has clearly been broken, and until networking is as reliable and as easy to set up as in Windows, (x/l/k)ubuntu will not be suitable for typical home users. -- 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/1666432 Title: Internet drops every few minutes on wired and wireless connection Status in network-manager package in Ubuntu: Confirmed Bug description: Internet drops every 1-30 minutes when connected via wired or wireless (i.e., this is a problem on both wired and wireless) even though connection icon indicates the computer is still connected. Disconnecting and reconnecting via the connection icon resets internet temporarily until the next time. Dropped internet is discovered with "The site can't be reached" screens in Chromium, or error messages when downloading/updating in Terminal, or missing connection in Ubuntu Software app, or stalled syncing in Insync application (occurred even without Insync). Internet drops more frequently on wireless than on wired. It seems to disconnect more frequently with heavier internet use (e.g., downloading multiple files, opening several webpages in quick succession). This is a fresh install (yesterday) of Ubuntu 16.04 on a Dell Inspiron 15 5567 (dual boot). It occurs when running Live CD as well though. Ethernet and wifi both work without randomly disconnecting in Windows 10 on the same machine, and ethernet and wifi work on other machines running Ubuntu and Windows with the same router, so it is not a hardware or router issue. Output from sudo lshw -class network *-network description: Wireless interface product: Wireless 3165 vendor: Intel Corporation physical id: 0 bus info: pci@0000:02:00.0 logical name: wlp2s0 version: 79 serial: 58:fb:84:55:21:52 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=iwlwifi driverversion=4.4.0-62-generic firmware=17.352738.0 ip=192.168.1.15 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn resources: irq:283 memory:df100000-df101fff *-network description: Ethernet interface product: RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:03:00.0 logical name: enp3s0 version: 07 serial: 18:db:f2:3c:d5:37 size: 10Mbit/s capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8106e-1_0.0.1 06/29/12 latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:279 ioport:d000(size=256) memory:df000000-df000fff memory:d0300000-d0303fff ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: network-manager 1.2.2-0ubuntu0.16.04.3 ProcVersionSignature: Ubuntu 4.4.0-62.83-generic 4.4.40 Uname: Linux 4.4.0-62-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.5 Architecture: amd64 CurrentDesktop: Unity Date: Tue Feb 21 16:36:55 2017 IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback InstallationDate: Installed on 2017-02-20 (1 days ago) InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) IpRoute: default via 192.168.1.1 dev wlp2s0 proto static metric 600 169.254.0.0/16 dev wlp2s0 scope link metric 1000 192.168.1.0/24 dev wlp2s0 proto kernel scope link src 192.168.1.15 metric 600 NetworkManager.state: [main] NetworkingEnabled=true WirelessEnabled=true WWANEnabled=true SourcePackage: network-manager UpgradeStatus: No upgrade log present (probably fresh install) nmcli-dev: DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH wlp2s0 wifi connected /org/freedesktop/NetworkManager/Devices/0 pr500k-9912ec-1 36301ded-0ac5-4a86-9621-87290ef159af /org/freedesktop/NetworkManager/ActiveConnection/5 enp3s0 ethernet unavailable /org/freedesktop/NetworkManager/Devices/1 -- -- -- lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/2 -- -- -- nmcli-nm: RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN running 1.2.2 connected started full enabled enabled enabled enabled enabled To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1666432/+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