Host Unreachable until I send some pings

Question

I just bought a Pi 3, and installed Raspbian on it. Now my Pi is working headless, connected via WiFi, but I have a strange behaviour with it. It seems that the Pi's WiFi connection is somewhat sleeping until I send some pings. Here is the log of the ping command:

C:\Users\Lorthirk>ping -t 192.168.1.61

Esecuzione di Ping 192.168.1.61 con 32 byte di dati:
Risposta da 192.168.1.69: Host di destinazione non raggiungibile.
  [Message repeated 99 times]
Risposta da 192.168.1.61: byte=32 durata=63ms TTL=64
Risposta da 192.168.1.61: byte=32 durata=81ms TTL=64
Risposta da 192.168.1.61: byte=32 durata=101ms TTL=64
Risposta da 192.168.1.61: byte=32 durata=21ms TTL=64
Risposta da 192.168.1.61: byte=32 durata=39ms TTL=64

("Host di destinazione non raggiungibile" means "Host unreachable" in Italian).

So it seems that the WiFi goes in some sleep state, and gets awaken somehow after some pings. Am I right? Is this a known behaviour? Can I do anything to prevent it?

I found [this answer](http://raspberrypi.stackexchange.com/questions/34794/how-to-disable-wi-fi-dongle-sleep-mode) and noticed that I had power saving enabled for wlan0. Now I disabled it, I'll report back tomorrow with the results — Claudio Mezzasalma, Mar 16 '16 at 11:52
My personal experience is, that this behavior is familiar on all models of the Pi, whether they have a wireless dongle or on-board wifi, but what's really strange is, that some devices always have this issue while others never have it with all devices running identical clean builds. — Wim Ombelets, Apr 16 '16 at 20:13

score 0 · Answer 1 · edited Mar 17 '16 at 10:06

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The problem is that the Broadcom firmware isn't quite handling the power management correctly. If you

sudo apt-get update 
sudo apt-get upgrade

It has now been fixed / worked around (power management has been disabled until the driver is fixed).

edited Mar 17 '16 at 10:06

Ghanima

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answered Mar 16 '16 at 21:31

GSH

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That is more and less what I did manually (see my answer). Thanks! – Claudio Mezzasalma Mar 17 '16 at 09:58

score 0 · Accepted Answer · edited Apr 13 '17 at 12:56

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I found this answer and noticed that I had power saving enabled for wlan0. Now I disabled it, I'll report back tomorrow with the results

edited Apr 13 '17 at 12:56

Community

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answered Mar 17 '16 at 09:58

Claudio Mezzasalma

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Host Unreachable until I send some pings

2 Answers2