[Solved] Wi-Fi connected but cannot ping external address

celebrimbor · 2014-05-28 18:25:54

Hi! I'm using NetworkManager to connect to my university's Wi-Fi (Using Tunneled TLS+PAP authentication) on my laptop.

The laptop connects, works well for sometime (~30 minutes) and then suddenly stops working. I mean Wi-Fi stays connected, I can ping localhost and router but cannot ping Google or any other external site.

Some more information about my hardware:

lspci -k

yields:

01:00.0 Network controller: Intel Corporation Centrino Advanced-N 6235 (rev 24)
        Subsystem: Intel Corporation Centrino Advanced-N 6235 AGN
        Kernel driver in use: iwlwifi
        Kernel modules: iwlwifi

dmesg | grep iwlwifi

yields:

[   10.782343] iwlwifi 0000:01:00.0: enabling device (0000 -> 0002)
[   10.782447] iwlwifi 0000:01:00.0: can't disable ASPM; OS doesn't have ASPM control
[   10.782549] iwlwifi 0000:01:00.0: irq 46 for MSI/MSI-X
[   11.370269] iwlwifi 0000:01:00.0: loaded firmware version 18.168.6.1 op_mode iwldvm
[   12.448590] iwlwifi 0000:01:00.0: CONFIG_IWLWIFI_DEBUG disabled
[   12.448599] iwlwifi 0000:01:00.0: CONFIG_IWLWIFI_DEBUGFS disabled
[   12.448605] iwlwifi 0000:01:00.0: CONFIG_IWLWIFI_DEVICE_TRACING enabled
[   12.448611] iwlwifi 0000:01:00.0: Detected Intel(R) Centrino(R) Advanced-N 6235 AGN, REV=0xB0
[   12.448674] iwlwifi 0000:01:00.0: L1 Disabled; Enabling L0S
[   25.986369] iwlwifi 0000:01:00.0: L1 Disabled; Enabling L0S
[   25.993170] iwlwifi 0000:01:00.0: Radio type=0x2-0x1-0x0
[   26.265477] iwlwifi 0000:01:00.0: L1 Disabled; Enabling L0S
[   26.272241] iwlwifi 0000:01:00.0: Radio type=0x2-0x1-0x0

Following the troubleshooting suggestion on the Wiki, I've tried disabling 802.11n and enabling software encryption. I've also tried disabling power-saving for wireless adapter by adding a udev rule but nothing helps.

Wi-Fi works just fine on Windows. The download speed on Linux is also 40% of what I get on Windows. What should I change to get everything back to normal?

Thanks in advance!

Last edited by celebrimbor (2014-06-04 19:34:54)

ewaller · 2014-05-28 18:32:15

What services are running? Please post the output of systemctl --type=service --no-pager

celebrimbor · 2014-05-28 19:56:29

ewaller wrote:

What services are running? Please post the output of systemctl --type=service --no-pager

UNIT                                                            LOAD   ACTIVE SUB     DESCRIPTION
dbus.service                                                    loaded active running D-Bus System Message Bus
getty@tty1.service                                              loaded active running Getty on tty1
kdm.service                                                     loaded active running K Display Manager
kmod-static-nodes.service                                       loaded active exited  Create list of required static device nodes for the current kern
lm_sensors.service                                              loaded active exited  Initialize hardware monitoring sensors
NetworkManager.service                                          loaded active running Network Manager
polkit.service                                                  loaded active running Authorization Manager
rtkit-daemon.service                                            loaded active running RealtimeKit Scheduling Policy Service
systemd-backlight@backlight:acpi_video0.service                 loaded active exited  Load/Save Screen Backlight Brightness of backlight:acpi_video0
systemd-backlight@backlight:intel_backlight.service             loaded active exited  Load/Save Screen Backlight Brightness of backlight:intel_backlig
systemd-fsck@dev-disk-by\x2duuid-2d51872f\x2d57af\x2d4523\x2dbd9a\x2dc42b2f25eeec.service loaded active exited  File System Check on /dev/disk/by-uuid/2d51872f-57af-4523-bd9a-c
systemd-fsck@dev-disk-by\x2duuid-7473\x2d0679.service           loaded active exited  File System Check on /dev/disk/by-uuid/7473-0679
systemd-journald.service                                        loaded active running Journal Service
systemd-logind.service                                          loaded active running Login Service
systemd-modules-load.service                                    loaded active exited  Load Kernel Modules
systemd-random-seed.service                                     loaded active exited  Load/Save Random Seed
systemd-remount-fs.service                                      loaded active exited  Remount Root and Kernel File Systems
systemd-rfkill@rfkill0.service                                  loaded active exited  Load/Save RF Kill Switch Status of rfkill0
systemd-rfkill@rfkill1.service                                  loaded active exited  Load/Save RF Kill Switch Status of rfkill1
systemd-sysctl.service                                          loaded active exited  Apply Kernel Variables
systemd-tmpfiles-setup-dev.service                              loaded active exited  Create Static Device Nodes in /dev
systemd-tmpfiles-setup.service                                  loaded active exited  Create Volatile Files and Directories
systemd-udev-trigger.service                                    loaded active exited  udev Coldplug all Devices
systemd-udevd.service                                           loaded active running udev Kernel Device Manager
systemd-update-utmp.service                                     loaded active exited  Update UTMP about System Boot/Shutdown
systemd-user-sessions.service                                   loaded active exited  Permit User Sessions
systemd-vconsole-setup.service                                  loaded active exited  Setup Virtual Console
udisks2.service                                                 loaded active running Disk Manager
upower.service                                                  loaded active running Daemon for power management
user@1000.service                                               loaded active running User Manager for UID 1000
wpa_supplicant.service                                          loaded active running WPA supplicant

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

31 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.

ewaller · 2014-05-28 21:02:20

Thanks. I was looking to see if there were any conflicts with multiple things controlling your network. It looks good.

When the problem occurs, can you ping sites by IP? Try 66.211.214.131 (that is an Arch Linux address).
If not, what is the output of traceroute for that address?

What the problem occurs, look in /etc/resolv.conf and see if the nameserver is rational. I would ordinarily suggest you change that to 8.8.8.8 (A Google DNS server), but I don;t know how that would work in your network.

celebrimbor · 2014-05-28 23:30:02

Thanks for the reply!

I cannot ping sites by either URL or IP address.

I am using Google Public DNS and OpenDNS in addition to what is automatically generated by NetworkManager, i.e. my /etc/resolv.conf is:

# Generated by resolvconf
nameserver 128.91.18.1
nameserver 128.91.49.1
nameserver 128.91.94.1
nameserver 208.67.222.222
nameserver 8.8.8.8

When the problem occurs, the output of traceroute on 8.8.8.8 is

traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
 1  vaikunth (158.130.223.8)  3008.247 ms !H  3008.184 ms !H  3008.175 ms !H

ewaller · 2014-05-29 01:36:37

But you can ping your gateway. right?
It appears that packets get as far as your school, but die there. I am not sure where to go from here.

celebrimbor · 2014-05-29 09:46:03

Okay. Thanks anyways for the help!

I asked Computer Connection office of the school but they said they only provide support for Windows and OSX. It seems I will have to make-do with restarting the connection everytime this happens.

Thanks again!

orschiro · 2014-05-29 10:41:33

@celembrimbor

Have you already tried another network manager, such as netctl?

Can you share the OSX guide of your university? Maybe it helps to set-up Linux accordingly.

tomk · 2014-05-29 10:50:40

Check dmesg immediately after it stops working.

celebrimbor · 2014-06-03 21:48:08

@orschiro and @tomk Thanks for your reply.

Here's the guide provided by my university:
https://secure.www.upenn.edu/computing/ … ect-wizard

Edit: I had posted the same link as above for linux
And here's the guide for Linux distros:
http://www.seas.upenn.edu/cets/answers/ … linux.html

I tried netctl, connman, and Wicd as well but the same problem persists.

dmesg for iwlwifi drivers is as posted in the original post.

Last edited by celebrimbor (2014-06-04 19:36:36)

ewaller · 2014-06-04 02:41:22

First, Allow me to congratulate you on attending University of Pennsylvania. Well done.

Those instructions you linked have to be the most hideous thing I have ever seen. You have to support either Active X or Java Applets in the browser? Ouch.
Those instructions do indicate that NetworkManager will be launched by their little goat rope. When I checked your services, I was checking to verify that things like NetworkManager were not being started as a service. It never occurred to me that NetworkManager would be started by some other unseen hand. I think we found that unseen hand.

Try this. I don't like to recommend a specific solution; it should be to the taste of the individual. In this case, however, configure your system to use NetworkManager and nothing else. Then see if it plays nice in your university's sandbox.

celebrimbor · 2014-06-04 19:34:21

Thank you very much! Though my department is not as good as some of the schools in California.

That connection guide is pretty dated and that unseen hand fails to communicate with NetworkManager (Tried on Ubuntu 14.04, Fedora 20, and Crunchbang). The guys I've met who use Linux connect to campus-network by either using wired connection or installing Linux inside a virtual machine.

I configured my system to use NetworkManager and the condition has indeed improved a bit. Instead of having half-hourly disconnections, it works for 1-2 hours and then I have to restart the connection. Thanks again for the suggestion! I think I can live with this.

Arch Linux

#1 2014-05-28 18:25:54

[Solved] Wi-Fi connected but cannot ping external address

#2 2014-05-28 18:32:15

Re: [Solved] Wi-Fi connected but cannot ping external address

#3 2014-05-28 19:56:29

Re: [Solved] Wi-Fi connected but cannot ping external address

#4 2014-05-28 21:02:20

Re: [Solved] Wi-Fi connected but cannot ping external address

#5 2014-05-28 23:30:02

Re: [Solved] Wi-Fi connected but cannot ping external address

#6 2014-05-29 01:36:37

Re: [Solved] Wi-Fi connected but cannot ping external address

#7 2014-05-29 09:46:03

Re: [Solved] Wi-Fi connected but cannot ping external address

#8 2014-05-29 10:41:33

Re: [Solved] Wi-Fi connected but cannot ping external address

#9 2014-05-29 10:50:40

Re: [Solved] Wi-Fi connected but cannot ping external address

#10 2014-06-03 21:48:08

Re: [Solved] Wi-Fi connected but cannot ping external address

#11 2014-06-04 02:41:22

Re: [Solved] Wi-Fi connected but cannot ping external address

#12 2014-06-04 19:34:21

Re: [Solved] Wi-Fi connected but cannot ping external address

Board footer