I can connect to and use wireless access points. After several minutes, however, I can no longer use them. The task bar applet shows a connection, but I can't send or receive data. Using service network-manager restart fixes the problem, but only temporarily, and I'm getting very tired of having to do it constantly.
I've read page after page on this site and elsewhere of lists of commands to run. Here's a summary of the information I've found as a result:
logical name: wlp4s0
driver=iwlwifi
04:00.0 Network controller: Intel Corporation Wireless 8260 (rev 3a)
I'm on a Lenovo ThinkPad T560.
iwconfig indicates Power Management is on.
rfkill indicates nothing is blocked, hard or soft
I've blocked IPv6 by adding
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
to the /etc/sysctl.conf config file and rebooting, but that did nothing.
For the present, I'm more interested in learning how to figure out what the problem is than in fixing it. How do I find out what's going wrong?
Info Edit 1: When this happens, I suddenly cannot load web pages. I cannot ping my default gateway (100% packet loss), and I cannot ping sites by name ("unknown host").
Info Edit 2: I tried turning Power Management off using $ sudo iwconfig <wlan0> power off. The problem recurred, even as I confirmed using iwconfig that Power Management remained off. The problem also happens regardless of whether I'm on battery or cable power.
When the disconnection happens, there is little change in the output of iwconfig. In particular, these parameters stay nearly constant:
Bit-rate=866.7 Mb/s
Tx-Power=22 dBm
Link Quality=70/70
Signal level=-40 dBm
Rx invalid nwid:0
Rx invalid crypt:0
Rx invalid frag:0
Tx excessive retries:0
Access Point remains a constant, valid MAC address throughout. The only output that changes is Invalid misc, which increases in count noticeably and continuously after the disconnection.
Meta Edit: Someone has linked to a similar question at Unstable wifi with intel 8260 [8086:24f3] (rev 3a) on Ubuntu 16.04 running on Lenovo P50. That user seems to have a more severe problem than I do. I don't lose sight of networks or have the applet icon change, I just stop being able to send and receive internet data, as if the connection is being throttled down to nothing.
In any event, I emphasize that there is no resolution or accepted answer on that question, and no activity in nearly a year. The existence of this similar question does not help me solve my problem.
It could be that you are still connected but dns has got messed up.
If it's not that, what is the output of
– Joe P Jun 01 '17 at 21:17iwconfig? Do you see errors and/or a drop in quality?sudo iwconfig _ifname_ power offThis helps some people. See https://askubuntu.com/questions/85214/how-can-i-prevent-iwconfig-power-management-from-being-turned-on for example.
– Joe P Jun 01 '17 at 21:31