R8000 Smart Connect and OSX Sleep Wake crashes
For the past year I've been living with random sleep wake failure crashes on my 2015 MAC Air 10.11.6 and have never had the time to actually debug. Well its xmas and holidays and after 3 crashes in the last 5 days after sleep I thought I would spend some time looking through the logs to see what is actually happening. My R8000 is running firmware 220.127.116.11_1.1.2.
I have smart connect enabled on my 5G band and my MAC can connect to both the channels and authenticate with no problems. I've tried this by connecting and disconnecting other 5G devices until the MAC picks between channels 40 and 153 (thats what is set on the R8000). To prove that this is in fact correct I also tried manually to connect to both bands using the tool at https://github.com/qpSHiNqp/airport-bssid.
The interesting thing here is that the upper channel is not normally broadcast. The BSSID however does randomly pop up in a scan (using the MAC wifi diagnosis) where as the lower band is always available and broadcast. If I use the tool I can connect to the lower band BSSID with no problems. However, as the higher band is only broadcast sparodically i have to repeatively try the upper BSSID. If the timing is right I can connect directly to the BSSID without any issues.
The problem is this behaviour appears to upset the MAC OSX BRCM4360 drivers and results in the machine crashing but only if appnap is used (machine randomly wakes up to connect to the net). When app nap is available then what I think is happening is that the wifi connects to the lower 5G band, then does a scan and finds that the upper band is available and then tries to connect to it. I think that at times there is a race condition and that by the time the MAC tries to connect the upper band is no longer available. What happens then is that the authenication of RSN fails and the MAC crashes.
While this appears to be an apple issue I'm wondering why is the upper 5G band sparodically advertsied? This this did not happen I would assume that the MAC would not crash.... turning appnap off by the way stops the crashes on elcap. While on holidays I'm going to try turning off smart connect and see if that also stops the issue. I suspect that it will but time will tell.
In case your interested below are the outcomes of my investigations. Any suggestions would be appreciated but this message was more for information than asking for a fix and in case some one else is having problems.
I have the logs but can not include them here dues to the message size limitations. Hope this helps anyone else with MAC Sleep Wake crashes and Netgear modems with smart connect.
Re: R8000 Smart Connect and OSX Sleep Wake crashes
Disabled smart connect, enabled napapp, and every thing works fine. I then broke out a wifi analyzer and looked at the bands and see that when smart connect is enabled that the beacon pulses on and off frequently for the 2nd band when smart connect is enabled. I've then searched based on this item and appears that this is a known issue reported in these forums for over a year without any resolution. Seems that smart connect netgear devices and MAC OSX have a dislike of each other. Given the 12 months in passing since the original report about the pulsing of the second band I would say that this appears to be normal. The only solution here seems to be run the 5G bands as separate SSIDs.