Thinkpad X1C6 wireless/wifi drops from time to time

ackerleytng · 2019-08-18 04:57:41

I'm running on battery, and I'm using netctl and netctl-auto to manage my wifi connection.

Once in a while, wireless connectivity would drop - my thinkpad continues to have an ip address on the local network, but I can no longer ping my router (192.168.1.1) - so it's not a DNS problem - and I cannot access the Internet.

I've checked journalctl and dmesg but there doesn't seem to be any logs relating to this issue. rfkill shows all devices (wifi and bluetooth) both hard and soft unblocked.

iwlist wlp2s0 power shows that the power is on

To reconnect, I restart the netctl-auto service and connectivity is back.

Sometimes, connectivity drops after a while again.

tcpdump shows many outgoing packets, just not a single one coming in... But I don't think I was doing anything that would have triggered any blocking...

Any tips on where to start debugging?

Last edited by ackerleytng (2019-08-18 05:00:28)

jasonwryan · 2019-08-18 05:22:03

systemctl list-unit-files --state=enabled

Moving to NC...

ackerleytng · 2019-08-18 05:33:36

$ systemctl list-unit-files --state=enabled

UNIT FILE          STATE  
autovt@.service    enabled
getty@.service     enabled
lenovo_fix.service enabled
tlp-sleep.service  enabled
tlp.service        enabled
remote-fs.target   enabled

6 unit files listed.

Thanks!

jasonwryan · 2019-08-18 06:23:06

So you have no network management service enabled?

ackerleytng · 2019-08-18 06:27:12

I've enabled netctl-auto, and I've been able to connect to wifi upon startup and stuff. Does this help?

 sudo systemctl status netctl-auto@wlp2s0.service                                                                                                                                                         ✘ 4 
● netctl-auto@wlp2s0.service - Automatic wireless network connection using netctl profiles
   Loaded: loaded (/usr/lib/systemd/system/netctl-auto@.service; enabled; vendor preset: disabled)
   Active: active (running) since Sun 2019-08-18 12:52:12 +08; 1h 33min ago
     Docs: man:netctl.special(7)
    Tasks: 3 (limit: 4915)
   Memory: 4.6M
   CGroup: /system.slice/system-netctl\x2dauto.slice/netctl-auto@wlp2s0.service
           ├─23854 wpa_supplicant -q -B -P /run/wpa_supplicant-wlp2s0.pid -i wlp2s0 -D nl80211,wext -c/run/netctl/wpa_supplicant-wlp2s0.conf -W
           ├─23858 wpa_cli -i wlp2s0 -p /run/wpa_supplicant -B -a /usr/lib/netctl/auto.action
           └─32606 dhcpcd -4 -q -t 30 -K -L wlp2s0

jasonwryan · 2019-08-18 06:30:26

One of the common reasons for network dropouts is conflicting services; you didn't have any enabled, so that can be ruled out...

After a drouput, look at your journal and dmesg for clues as to what is happening.

ackerleytng · 2019-08-18 13:31:00

It just happened again. I looked in dmesg:

Aug 18 20:10:14 ackerleytng-x1c6 systemd[1]: systemd-rfkill.service: Succeeded.
-- Subject: Unit succeeded
-- Defined-By: systemd
-- Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- The unit systemd-rfkill.service has successfully entered the 'dead' state.
Aug 18 20:10:14 ackerleytng-x1c6 audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-rfkill comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
Aug 18 20:10:14 ackerleytng-x1c6 kernel: audit: type=1131 audit(1566130214.143:228): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-rfkill comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? a>
Aug 18 20:10:17 ackerleytng-x1c6 systemd[1]: tlp-sleep.service: Succeeded.
-- Subject: Unit succeeded
-- Defined-By: systemd
-- Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- The unit tlp-sleep.service has successfully entered the 'dead' state.
Aug 18 20:10:17 ackerleytng-x1c6 kernel: audit: type=1131 audit(1566130217.103:229): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=tlp-sleep comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=?>
Aug 18 20:10:17 ackerleytng-x1c6 audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=tlp-sleep comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
Aug 18 20:10:17 ackerleytng-x1c6 systemd[1]: Stopped TLP suspend/resume.
-- Subject: A stop job for unit tlp-sleep.service has finished
-- Defined-By: systemd
-- Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- A stop job for unit tlp-sleep.service has finished.
-- 
-- The job identifier is 5360 and the job result is done.
Aug 18 20:10:18 ackerleytng-x1c6 dhcpcd[28808]: wlp2s0: leased 192.168.1.116 for 43200 seconds
Aug 18 20:10:18 ackerleytng-x1c6 dhcpcd[28808]: wlp2s0: adding route to 192.168.1.0/24
Aug 18 20:10:18 ackerleytng-x1c6 dhcpcd[28808]: wlp2s0: adding default route via 192.168.1.1
Aug 18 20:10:18 ackerleytng-x1c6 dhcpcd[28808]: forked to background, child pid 28897

That was an hour ago - and it looks like this was because I woke my thinkpad up - seems ok to me.

Nothing stands out in dmesg either. Any other things I should check?

ackerleytng · 2019-08-18 14:05:27

Tried

ip monitor

Here's the output. How do I understand that?

https://pastebin.com/hexLcHiW

ackerleytng · 2019-08-18 15:08:03

I did a bit more sleuthing, tcpdump on my router seems to indicate that the router is replying to the ARP requests, but my laptop is not receiving it.

Why would it randomly start and stop receiving?

ackerleytng · 2019-08-24 15:28:58

Figured it out - even though tlp-stat showed that my wireless was on

+++ Wireless
bluetooth = on
wifi      = on
wwan      = none (no device)

hci0(btusb)                   : bluetooth, not connected
wlp2s0(iwlwifi)               : wifi, connected, power management = on

The wireless was actually powered off or on low power or something.

Doing

sudo iw dev wlp2s0 set power_save off

brought the network connection back up again.

I eventually disabled wifi power saving completely in tlp settings.

Arch Linux

#1 2019-08-18 04:57:41

Thinkpad X1C6 wireless/wifi drops from time to time

#2 2019-08-18 05:22:03

Re: Thinkpad X1C6 wireless/wifi drops from time to time

#3 2019-08-18 05:33:36

Re: Thinkpad X1C6 wireless/wifi drops from time to time

#4 2019-08-18 06:23:06

Re: Thinkpad X1C6 wireless/wifi drops from time to time

#5 2019-08-18 06:27:12

Re: Thinkpad X1C6 wireless/wifi drops from time to time

#6 2019-08-18 06:30:26

Re: Thinkpad X1C6 wireless/wifi drops from time to time

#7 2019-08-18 13:31:00

Re: Thinkpad X1C6 wireless/wifi drops from time to time

#8 2019-08-18 14:05:27

Re: Thinkpad X1C6 wireless/wifi drops from time to time

#9 2019-08-18 15:08:03

Re: Thinkpad X1C6 wireless/wifi drops from time to time

#10 2019-08-24 15:28:58

Re: Thinkpad X1C6 wireless/wifi drops from time to time

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