amcdonley
Posts: 175
Joined: Mon Jan 26, 2015 5:56 pm
Location: Florida, USA

Pi3 onboard Wifi: Ping Request timeouts

Fri Nov 24, 2017 9:12 pm

My robot has a (new) Pi3 running updated Raspbian Stretch, with a remote ssh session over wlan0, and a Python2.7 multi-process sensor status loop running, with a 15 minute top load of 0.10

When I ping the bot via WiFi, I see about 10 "Request timeout for icmp_seq x" per hour.
With power management off, it still sees 5 timeouts per hour.
I'd like to also try disabling 802.11n

ping reports:

Code: Select all

PING 10.0.0.xxx (10.0.0.xxx): 56 data bytes
64 bytes from 10.0.0.xxx: icmp_seq=0 ttl=64 time=5.299 ms
64 bytes from 10.0.0.xxx: icmp_seq=1 ttl=64 time=5.552 ms
64 bytes from 10.0.0.xxx: icmp_seq=2 ttl=64 time=4.873 ms
64 bytes from 10.0.0.xxx: icmp_seq=3 ttl=64 time=6.378 ms
64 bytes from 10.0.0.xxx: icmp_seq=4 ttl=64 time=5.790 ms
64 bytes from 10.0.0.xxx: icmp_seq=5 ttl=64 time=5.582 ms
64 bytes from 10.0.0.xxx: icmp_seq=6 ttl=64 time=5.692 ms
and ping 10.0.0.xxx | grep timeout for 3 hours reports:

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Request timeout for icmp_seq 145
Request timeout for icmp_seq 541
Request timeout for icmp_seq 685
Request timeout for icmp_seq 782
Request timeout for icmp_seq 826
Request timeout for icmp_seq 891
Request timeout for icmp_seq 1443
Request timeout for icmp_seq 1564
Request timeout for icmp_seq 1693
Request timeout for icmp_seq 1921
Request timeout for icmp_seq 1938
Request timeout for icmp_seq 2195
Request timeout for icmp_seq 2287
Request timeout for icmp_seq 2339
Request timeout for icmp_seq 2372
Request timeout for icmp_seq 2660
Request timeout for icmp_seq 3490
Request timeout for icmp_seq 4962
Request timeout for icmp_seq 5368
Request timeout for icmp_seq 6053
Request timeout for icmp_seq 6514
Request timeout for icmp_seq 7063
Request timeout for icmp_seq 8136
Request timeout for icmp_seq 9129
Request timeout for icmp_seq 9488
Request timeout for icmp_seq 9830
Request timeout for icmp_seq 9981
Request timeout for icmp_seq 10268
Request timeout for icmp_seq 10589
ifconfig reports no errors:

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lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        loop  txqueuelen 1  (Local Loopback)
        RX packets 2190762  bytes 136578808 (130.2 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2190762  bytes 136578808 (130.2 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.0.0.184  netmask 255.255.255.0  broadcast 10.0.0.255
        ether b8:27:eb:62:b9:35  txqueuelen 1000  (Ethernet)
        RX packets 100208  bytes 8449369 (8.0 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 90041  bytes 13594333 (12.9 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        
iwconfig wlan0 reports:

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wlan0     IEEE 802.11  ESSID:"xxxx"  
          Mode:Managed  Frequency:2.412 GHz  Access Point: xx:xx:xx:xx:xx   
          Bit Rate=72.2 Mb/s   Tx-Power=31 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          Link Quality=65/70  Signal level=-45 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:296  Invalid misc:0   Missed beacon:0

==========
With power Management off, (sudo iwconfig wlan0 power off), it still sees about 5 timeouts per hour:

Code: Select all

Request timeout for icmp_seq 47
Request timeout for icmp_seq 1118
Request timeout for icmp_seq 1141
Request timeout for icmp_seq 2197
Request timeout for icmp_seq 3098
. . .
another ping run: 

1523 packets transmitted, 1521 packets received, 0.1% packet loss
round-trip min/avg/max/stddev = 1.582/9.401/405.635/35.838 ms
iwconfig wlan0 reports:

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wlan0     IEEE 802.11  ESSID:"xxxx"  
          Mode:Managed  Frequency:2.412 GHz  Access Point: xx:xx:xx:xx:xx   
          Bit Rate=72.2 Mb/s   Tx-Power=31 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=65/70  Signal level=-45 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:24  Invalid misc:0   Missed beacon:0

Anyone know how I can try 11n_disable=1 with the Pi3 onboard WiFi?

sora03
Posts: 193
Joined: Mon Dec 29, 2014 4:11 pm
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Re: Pi3 onboard Wifi: Ping Request timeouts

Sat Nov 25, 2017 7:07 am

you can write a script to check if the network is up (by pinging or other methods) then reconnect if ping timed out. you can execute the script via cron jobs
11n_disable Iforgot on how I disabled mine but it is modification in modprobe config
FLOSS enthusiast, Debian user (linux-libre)

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DougieLawson
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Re: Pi3 onboard Wifi: Ping Request timeouts

Mon Nov 27, 2017 8:08 am

What kernel version are you running?
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amcdonley
Posts: 175
Joined: Mon Jan 26, 2015 5:56 pm
Location: Florida, USA

Re: Pi3 onboard Wifi: Ping Request timeouts

Mon Nov 27, 2017 10:55 am

DougieLawson wrote:
Mon Nov 27, 2017 8:08 am
What kernel version are you running?
uname -a:

Linux RWPi 4.9.41-v7+ #1023 SMP Tue Aug 8 16:00:15 BST 2017 armv7l GNU/Linux

vcgencmd version:
Aug 8 2017 12:05:45
Copyright (c) 2012 Broadcom
version 196063438d7bb0769861c86f948ae653727adb7e (clean) (release)

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DougieLawson
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Re: Pi3 onboard Wifi: Ping Request timeouts

Mon Nov 27, 2017 11:27 am

Run this
sudo apt update && sudo apt -y dist-upgrade && sudo reboot

Or for the brave and foolhardy
sudo rpi-update && sudo reboot
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amcdonley
Posts: 175
Joined: Mon Jan 26, 2015 5:56 pm
Location: Florida, USA

Re: Pi3 onboard Wifi: Ping Request timeouts

Mon Nov 27, 2017 11:58 am

DougieLawson wrote:
Mon Nov 27, 2017 11:27 am
Run this
sudo apt update && sudo apt -y dist-upgrade && sudo reboot

Or for the brave and foolhardy
sudo rpi-update && sudo reboot
The following packages will be upgraded:
libsmbclient libwbclient0 samba-common samba-libs
4 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

your firmware was successfully updated to e4b56bb7efe47319e9478cfc577647e51c48e909

uname -a:
Linux RWPi 4.9.65-v7+ #1056 SMP Fri Nov 24 13:58:07 GMT 2017 armv7l GNU/Linux

vcgencmd version
Nov 17 2017 15:23:56
Copyright (c) 2012 Broadcom
version 2c2faa4c5e38cc04d01245905b8338e8fc55ee0d (clean) (release)

(I'm probably tilting windmills since I have an Xfinity router. I'm thinking of putting my old router up wired off the Xfinity router and see if the RPi3 acts differently.)

Do I need to re-run raspi-config? It seems like my SPI might be off - My robot can't feel his toes (SPI interface card is reporting "Battery voltage is 0.0, Shutting down to protect myself" )

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DougieLawson
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Re: Pi3 onboard Wifi: Ping Request timeouts

Mon Nov 27, 2017 12:28 pm

You've now got a kernel that definitely includes the WiFi QoS fix, so it's probably external to the RPi now.
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