No internet connection through WLAN although connected to network

[yan]

In a fresh install of Kubuntu 16.04 on a ThinkPad t460s, I can connect wireless to the local WLAN, but I don't have an internet connection. A ping to the router doesn't work in that case.

After some minutes, the connection usually (but not always) works.

A LAN connection through the same router works, too. It seems that the problem doesn't occur in every WLAN, but in my home network (using an O2 box 6431) it always does.

The problem is reproducible with a Kubuntu Live CD/USB.

The following steps did not solve the problem:

- Reconnect to WLAN
- Using kernel 4.6 or 4.7
- Restarting NetworkManager and networking service
- Disable IPv6
- Factory reset of the o2 box
- Restart of the o2 box (sometimes it helps temporarily)
---
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
CurrentDesktop: KDE
DistroRelease: Ubuntu 16.04
InstallationDate: Installed on 2016-04-04 (294 days ago)
InstallationMedia: Kubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160323)
Package: linux (not installed)
Tags: xenial
Uname: Linux 4.7.4-040704-generic x86_64
UnreportableReason: The running kernel is not an Ubuntu kernel
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True

[yan (yannn)]

I filed the bug report here, too:
https://bugs.kde.org/show_bug.cgi?id=361655

I guess that's the right place.

[Launchpad Janitor (janitor)]

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

[Phillip Susi (psusi)]

So it is working now, and you can't reproduce the problem? If so then we can't really help. If you can reproduce it, please post the output of sudo ifconfig.

[yan (yannn)]

It works sometimes, and sometimes not. But it was suggested on bugs.kde.org (https://bugs.kde.org/show_bug.cgi?id=361655#c3) to file a bug report on bugzilla.gnome.org, so I did that:

https://bugzilla.gnome.org/show_bug.cgi?id=765578

The output of ifconfig is:

enp0s31f6 Link encap:Ethernet Hardware Adresse 50:7b:9d:ab:13:3a
          UP BROADCAST MULTICAST MTU:1500 Metrik:1
          RX-Pakete:88891 Fehler:0 Verloren:0 Überläufe:0 Fenster:0
          TX-Pakete:49000 Fehler:0 Verloren:0 Überläufe:0 Träger:0
          Kollisionen:0 Sendewarteschlangenlänge:1000
          RX-Bytes:111664327 (111.6 MB) TX-Bytes:7892646 (7.8 MB)
          Interrupt:16 Speicher:f1200000-f1220000

lo Link encap:Lokale Schleife
          inet Adresse:127.0.0.1 Maske:255.0.0.0
          inet6-Adresse: ::1/128 Gültigkeitsbereich:Maschine
          UP LOOPBACK RUNNING MTU:65536 Metrik:1
          RX-Pakete:2097 Fehler:0 Verloren:0 Überläufe:0 Fenster:0
          TX-Pakete:2097 Fehler:0 Verloren:0 Überläufe:0 Träger:0
          Kollisionen:0 Sendewarteschlangenlänge:1
          RX-Bytes:177943 (177.9 KB) TX-Bytes:177943 (177.9 KB)

wlp4s0 Link encap:Ethernet Hardware Adresse a4:34:d9:be:bd:f1
          inet Adresse:192.168.178.7 Bcast:192.168.178.255 Maske:255.255.255.0
          inet6-Adresse: fe80::a634:d9ff:febe:bdf1/64 Gültigkeitsbereich:Verbindung
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metrik:1
          RX-Pakete:271 Fehler:0 Verloren:0 Überläufe:0 Fenster:0
          TX-Pakete:560 Fehler:0 Verloren:0 Überläufe:0 Träger:0
          Kollisionen:0 Sendewarteschlangenlänge:1000
          RX-Bytes:55201 (55.2 KB) TX-Bytes:90151 (90.1 KB)

[Phillip Susi (psusi)]

Was that taken when it is working? We would need to see it when it is not working.

[yan (yannn)]

iirc I took that when it was not working. The WLAN part is wlp4s0. In this moment it's working again, so I can't check.

[yan (yannn)]

I have been struggling with this problem for two months now. Since it was suggested that this bug is a Network Manager bug, I had filed a report there: https://bugzilla.gnome.org/show_bug.cgi?id=765578

But after many attempts, it seems that this is not related to Network Manager. So I'm coming back here hoping to finally be able to use wireless without problems.

I'm currently running kernel 4.6 and Network Manager 1.2.0. After boot and after suspend, wireless doesn't work (most of the times), i.e. I'm connected to WLAN, but I have no internet access. Through ethernet (cable) it does work always. And after being connected through ethernet for a while, the wireless connection does work (with the cable unplugged).

See detailed reports in the bug report.

Can anybody please help me? It's so annoying to depend on a wired connection.

[yan (yannn)]

It seems some update a couple of weeks ago has solved the problem. I don't know which one, but at least I can use wireless connections without problems now.

[yan (yannn)]

And the problem is back again.. I didn't change anything and all of a sudden wireless connection isn't working, just as described above. So annoying.

[yan (yannn)]

Sorry, my bad: This time it was the networks' fault, not my computers'.

[yan (yannn)]

Unfortunately it's all back to what it was before. For some weeks everything worked just fine, but now it's been some days where there's almost never an Internet connection possible although connected to the WLAN.

[yan (yannn)]

After some time that the network worked without further problems, I'm now back to where I was before, but with some changes. After boot, there is no internet connection although I'm connected to my local WLAN. But after some minutes, the connection does work. Usually, after another (longer) period of time, the connection stops working again. I can't find anything that would trigger such behavior.

I noticed something: When I'm connected to my home network ("paula") and there is no internet connection, I can connect to a mobile hotspot of my smartphone and then I do have internet access. As soon as I reeconnect to my home network, the connection is broken again.

Today I ran the wireless info script (https://github.com/UbuntuForums/wireless-info) in three scenarios:

1) After boot, connected to home network, no internet connection
2) Connected to mobile hotspot instead of home network, internet connection is working
3) Connected to home network and waited a while, internet connection is working

I attach the three files with the output.

Can somebody please help me? It's so annoying - and it's been months already.

[Chris Guiver (guiverc)]

when it's "not working" can you ping (icmp echo request) your router?
"ping 192.168.1.1" (when using "paula" network)

if the answer is YES; you might want to try adding a "nameserver" to the /etc/resolv.conf DNS lookup file when you've problems. eg. adding the line "nameserver 8.8.8.8"

if this (dirty horrid work-around) works; you could could put in a file; you run when you have problems (say in /usr/local/bin/, or better ~/bin if you have one). this is NOT a fix; a thought about a dirty-work-around after discussion ended on #ubuntu earlier.

[Chris Guiver (guiverc)]

a comment in bugzilla.gnome noted your machine had changed bandwidth.
do you have problems with your wireless connection (paula) with other devices?
is it a crowded location (dorm/university or setting where lots of people use wireless devices)?
is there any fridge(refrigerator), microwave oven or like object that can block traffic between you & ruoter when you have issues?

ie. normal troubleshooting for wireless has been followed thru with?
any thoughts (another question I didn't get answer to on irc #ubuntu)

[yan (yannn)]

Thanks Chris!

> when it's "not working" can you ping (icmp echo request) your router?
> "ping 192.168.1.1" (when using "paula" network)

No, I can't.

> do you have problems with your wireless connection (paula) with other devices?

No, no other device has problems.

> is it a crowded location (dorm/university or setting where lots of people use wireless devices)?

No, it's a private appartment with max. 5 devices connected at the same time.

> is there any fridge(refrigerator), microwave oven or like object that can block
> traffic between you & ruoter when you have issues?

No, it happens when I'm right next to the router.

> ie. normal troubleshooting for wireless has been followed thru with?

I don't know what means "normal" but I have tried everything people have suggested so far.

[Chris Guiver (guiverc)]

Thanks Yan

Your responses point towards a module (driver) problem (yes bug) to me, and my 'dirty-workaround' won't help. I'll give it some thought and play around with the wireless on my x201 & t43 (closest I have to your t460) & see if I come up with anything. ps: today/tomorrow i'm unlikely to be on web; so expect response (my) thursday or later.

next dirty workaround|hack coming to mind is disabling & re-enabling wireless. have you tried this? or did it do anything?

[Chris Guiver (guiverc)]

just assigned bug to me. Yan don't get your hopes up; I'm not a dev, and won't be able to fix the problem, I just HOPE to come up with something better for you.

[Chris Guiver (guiverc)]

Yan: On 2016-06-27 you wrote
"After boot and after suspend, wireless doesn't work (most of the time.."

Can you please clarify?
ie. does NOT work (sometimes) after a suspend?
& after cold|re-boots, does it work all the time? or only sometimes?

re: my post #18; I was vague; command I was thinking of is
"sudo systemctl restart NetworkManager"
(note: NetworkManager is service name; case matters!); though if you prefer GUI, and try it that way let me know about that too; i just prefer commands)

When you have problems next time; try this command (or GUI equivalent) and please tell me if it helps. this is work-around.

[yan (yannn)]

Thank you for taking your time Chris!

> next dirty workaround|hack coming to mind is disabling & re-enabling wireless. have you tried this?
> or did it do anything?

What exactly do you mean? I tried "sudo service networking restart", but it didn't help.

> Can you please clarify?
> ie. does NOT work (sometimes) after a suspend?
> & after cold|re-boots, does it work all the time? or only sometimes?

Right night the connection does NEVER work after boot/restart. After some minutes, it does work. I'd have to check it again to be sure, but iirc the same happens after every suspend.

> re: my post #18; I was vague; command I was thinking of is
> "sudo systemctl restart NetworkManager"
> (note: NetworkManager is service name; case matters!); though if you prefer GUI, and try it that > way let me know about that too; i just prefer commands)

I will try it. What I have tried before is "sudo service networkmanager restart", but without any success.

[yan (yannn)]

"sudo systemctl restart NetworkManager" doesn't solve it, just checked.

[Chris Guiver (guiverc)]

Question: What did you see when you ran 'sudo systemctl restart NetworkManager' command?

Me, my x201 (thinkpad) has xubuntu-desktop + ubuntu-desktop + ubuntu-mate-desktop installed

I tried command in terminal on each of mate|xfce|unity. On each I saw a short delay; sometimes the panel wifi-applet|widget disappeared for an instant (your machine may be faster & you not even notice this) then 'applet' would re-appear, as a circling (however you'd describe it) as my wifi connection was re-established; ip address obtained etc.
Yan: Do you see this???

You have Kubuntu-desktop; a clash (with unity and/or mate) meant I couldn't install it on x201 to see how it'd appear on KDE. My t43 is no help; installed lubuntu but forgot to check its hardware; it's wireless card had been removed so its no help. My other machines are without wifi; or pre-historic (why I went for t43). This workstation has kubuntu-desktop; but alas no wifi & static IP so I doubt I'd see anything with the aforementioned command.

[yan (yannn)]

> Question: What did you see when you ran 'sudo systemctl restart NetworkManager' command?

There was no output. The applet/widget disappears for a second and then reappears. Then there is a moving circle that shows that it's reconnecting to wireless.

[Chris Guiver (guiverc)]

ok thanks Yan.
will have to re-read your prior attachments (bug reports) & look for something else.

[yan (yannn)]

One more thing: I just booted from USB with Kubuntu 16.04 and I couldn't reproduce the problem.

[yan (yannn)]

Regarding my last comment I again have to correct it: On a second try, the connection did not work, i.e. the problem was the same. It's all really weird.

[Chris Guiver (guiverc)]

thanks Yan

I saw both posts soon after post. #26 I suspected would fail unless bad-install due hardware glitch or sunspot (flipping bits in ram) etc so was expecting #27.
if I didn't get #27 you'd be getting commands to re-install your wifi modules.

[Chris Guiver (guiverc)]

this is a thought/hack only for consideration:

searching online: a debian[-testing] user had issues with a t460 (power-management or wake from suspend on battery; yes a different issue to you; {stefon:2016-03-26}) which was fixed with a later 4.5 kernel.

the following is a link to install another kernel should you feel comfortable to try.
http://ubuntuhandbook.org/index.php/2016/05/install-linux-kernel-4-6-ubuntu-16-04/

note: I would NOT delete your existing kernel. I am also assuming you have GRUB installed. If there are problems select an older kernel (at grub menu) & just remove (dpkg -r) the newer kernel.

This is something you might want to consider trying/testing. Any questions, please ask. (if you have ubuntu 16.10; a live boot of that would test same thing without altering your sdd|disk).

[yan (yannn)]

Thanks Chris. I have already tried both kernels 4.6 and 4.7 (currently running), but to no avail.

[Launchpad Janitor (janitor)]

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

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1566987

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[yan (yannn)]

apport-collect leads to this error:

ERROR: Could not import module, is a package upgrade in progress? Error: No module named PyQt5.QtCore
https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1451808

[yan (yannn)]

This might be related:

Not working network connection after boot
https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1434986

[biohazara (biohazara)]

Try to disable IPv6 on your home WLAN and see if you have the same problems. I set IPv6 to ignore on network manager for my home WLAN and it was the only way I could get it to work properly on 16.04. On 14.04 that problem doesn't exist.

[yan (yannn)]

No, biohazara, disabling IPv6 doesn't change anything.

[yan (yannn)]

Any more ideas? It's driving me nuts.

It seems now that this only happens in my home network using an o2 box 6431. Resetting it didn't change anything. Currently it seems that a restart of the router solves the problem temporarily (but before, it hadn't been like that, so maybe it's just luck).

[yan (yannn)]

apport information

[yan (yannn)]

apport information

[yan (yannn)]

Any more ideas? Please? I'm about to throw my notebook against wall every time I use it at home - which is 90% of the time.

[Stefano (stefano-d)]

I can confirm this bug which I can reproduce since many Ubuntu releases. This is why I switched to Fedora --> No problems!
I can confirm, that restarting Network Manager CAN help, but not always!
The best thing to do is to restart Network Manager and immediately refresh a web page. Pinging doesn't work reliable.
This time, I can reproduce this bug with Ubuntu 17.04 Alpha/Beta.
I attached some log messages if this can help.

[Stephan Woidowski (swoidowski)]

Having the same Problem. It's 17.04 (newest). I was asked by the system to type my passphrase into the field for network connection and after i've done, it seemed to connect but the connection failed without any message or some and due to the failing internet/network connection i can't send any bug report relating this problem.