DebuggingNetworkManager

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Debugging Central

This page is part of the debugging series — pages with debugging details for a variety of Ubuntu packages.

Bug Summary

If a network-manager bug report is about not being able to connect the title or summary should be in the format:

"[CHIPSET] cannot connect to (ENCRYPT_METHOD)"

where the CHIPSET is the wireless driver used and ENCRYPT_METHOD is the encryption method used by your wireless network.

Understanding your bug and getting more information

Getting debug logs

You can then follow developers' intructions on a bug report for the exact command line to use; or run it directly as such:

Getting NetworkManager debug logs

sudo /usr/lib/NetworkManager/debug-helper.py --nm debug

Then get the logs which will be written to /var/log/syslog. To disable it, pass info instead of debug in the above command, or reboot.

Getting ModemManager debug logs

sudo /usr/lib/NetworkManager/debug-helper.py --mm debug

Then get the logs which will be written to /var/log/syslog. To disable it, pass info instead of debug in the above command, or reboot.

See also DebuggingModemmanager.

Getting wpasupplicant debug logs

sudo /usr/lib/NetworkManager/debug-helper.py --wpa msgdump

Then get the logs which will be written to /var/log/syslog. To disable it, pass info instead of debug in the above command, or reboot.

Getting a capture of syslog

Mixing and mashing the above is perfectly acceptable as well if you want to see how NetworkManager and other parts of the stack interact together.

In order to understand whats going on and track down issues, its good to have a full log. To do so, capture the complete test case and submit the whole file (don't cut out what you think is important). Please add markers in the log file so the bug triager can easily see what actions the user takes at what point of time (this isn't essential, but helps a lot).

To capture the syslog, do:

 tail -n0 -f /var/log/syslog > /tmp/syslog

and to stop capturing do Ctrl-C (you will have to type your other commands in an other window or tab)

Adding markers is just like adding new lines with an editor that show the triager what happened at what point of time. You can also do this on the fly as you test with the command logger "[ clicked on wireless network 'ubuntu']" .

Example marker:

Sep  6 08:12:30 ...

[ clicked on wireless network 'ubuntu']

Sep  6 08:12:31 ...
...

Handling 3G / modem issues

An few extra things that are very helpful to add in case of issues with 3G:

The output of udevadm for tty devices, and output of lsusb:

$ udevadm info --query=all --path=/sys/class/tty/... --attribute-walk

$ lsusb

A Testcase

A good testcase is a step by step instruction to reproduce your bug starting with driver unloaded and NetworkManager stopped.

First, stop NetworkManager:

sudo service network-manager stop

Then unload your driver:

sudo modprobe -r DRIVER

Next, load the driver:

sudo modprobe DRIVER

and finally start NetworkManager:

sudo service network-manager start

DebuggingNetworkManager (last edited 2016-08-02 09:34:57 by penalvch)