More Logging for WiFi Events?

[Kevin K]

How do I enable logging of WiFi events?

I have an intermittent issue with 5 GHz WiFi on my AC88u. Once or twice a week, all 5 GHz clients disconnect. The 5 GHz SSID disappears from clients' list of SSIDs, and when I run a site survey from my cell phone, my Asus 5 GHz SSID is not listed. If I disable/re-enable 5 GHz WiFi on my router, everything is goes back to normal.

I need detailed logging of WiFi events (and process deaths and starts), in order to investigate.

 

[RMerlin]

How do I enable logging of WiFi events?

You can't.

 

[Pir8pete]

You can't.

but why can't there be? this poor guy needs to diag. the reasons why his 5g is giving issues

 

[ColinTaylor]

but why can't there be?

Because the wireless subsystem is closed source and doesn't provide any event information. You can't log what doesn't exist.

 

[Kevin K]

Because the wireless subsystem is closed source and doesn't provide any event information. You can't log what doesn't exist.

Understood. Is there a particular process which *should* be active when 5 GHz is enabled? At the very least, I could run a shell script to track if/when that process dies.

 

[ColinTaylor]

I have an intermittent issue with 5 GHz WiFi on my AC88u. Once or twice a week, all 5 GHz clients disconnect. The 5 GHz SSID disappears from clients' list of SSIDs, and when I run a site survey from my cell phone, my Asus 5 GHz SSID is not listed. If I disable/re-enable 5 GHz WiFi on my router, everything is goes back to normal.

I don't have an AC88U, but FWIW I had a similar issue with my old N66U and never got to the bottom of it. I just ended up scheduling a restart of the wireless subsystem at 7am each day.

I'm not aware of any userland processes that are specific to the 5GHz radio so I doubt that you'll find that any processes have "died". I think all the radio stuff runs independently of the router's OS. But you could have a look at acsd and eapd.

As your issue is with 5GHz only the first thing to eliminate is a DFS problem. Manually select a channel between 36 and 48 only and see if the problem disappears. If you are using channels above 48 it's possible it might be a "radar detection" issue, but you should see messages to that effect in the syslog.

 

[Kevin K]

Hmmm... I was seeing increasingly frequent crashes -- every few days, then every day, and then twice on Sunday. On Sunday afternoon, I re-loaded factory firmware, did a reset to factory defaults, and the ONLY changes I made to default configuration were to assign some modest passwords. I've now been 52 hours without losing 5 GHz. Could be a coincidence. I'm going to let it run a little longer before I start making changes, but it sure looks like either a firmware or a config problem can make the 5 GHz radio unstable.

 

[ScottW]

On Sunday afternoon, I re-loaded factory firmware, did a reset to factory defaults, and the ONLY changes I made to default configuration were to assign some modest passwords. I've now been 52 hours without losing 5 GHz.

@kevin... Any update on this? Did running the stock firmware solve this long term?

I'm having the same issue you described on my 88u with Merlin 380.65_2. The 5g radio just disappears, usually after 2-3 days of running perfectly stable. Wired and 2.4g clients continue working fine, and the Wireless Log still shows all the 5G devices connected -- but there is no signal, no ssid being broadcast, all 5g clients dropped. Restarting the 5g radio brings everything back -- for a few days.

The "Tools" page also shows both radio temps as "disabled", which Eric indicated was because the current GPL doesn't fully support rev A5 hardware (bcm 4366e?). Wondering if there could be something else not handled correctly, such that when a new GPL for 4366e is available the problem will be resolved.

 

[Kevin K]

Results are still preliminary. I can't say exactly which change fixed it. Restored to factory firmware and factory default settings and made only the absolute minimum changes and my 5 GHz has been stable since 4:24 PM on March 26.

It could have been the factory firmware; it could have been factory default settings; it could have been my epically long WiFi password; it could have been any of the dozens of settings I made. Maybe something went not-quite-right with the flash to Merlin.

All I can say for certain is that I was running with Merlin and many custom settings (unrelated to WiFi) and 5 GHz would just up and die, and now I'm running with a near-factory device and it is stable.

I'm slowly making a change to settings every few days, to get back to the state I'd like. I'm not sure when I'll re-flash to Merlin -- I really need my family to be out of the house for about 3 days for that!

Given your symptoms, I'd recommend setting it back to out-of-the-box state and seeing if that stabilizes it. If you discover the problem, please DO post a follow-up here. I'd like to know what fixes it.

 

[ColinTaylor]

@Kevin K What firmware version are you now using? Just so people know when they read this in the future.

 

[Kevin K]

Currently: 3.0.0.4.380_7266
Merlin was RT-AC88U_380.65_2.zip (my issues were before 65_4 was released).

 

[ScottW]

Restored to factory firmware and factory default settings and made only the absolute minimum changes and my 5 GHz has been stable since 4:24 PM on March 26.

Thanks for the follow-up. That uptime is definitely encouraging. Which specific firmware version are you using? [EDIT - I see you posted the answer as I was posting the question, please ignore!]

First thing I did after taking my 88u out of the box was load RMerlin 380.65_2, followed by a "factory reset". I don't change a lot of settings, but I do have a long list of dhcp reservations and typically about 28 clients (some wired, some 5g, some 2.4g), so it is a "busy" environment. There is also an access point, with some clients moving between the router and AP during the day. I am running ab-solution for ad blocking. IP6 enabled and seems stable. No ftp, light samba use, vpn server active but seldom used, no dlna.

When this happens, it seems as if the 5g radio is just "locked up" -- because everything else (wired clients, 2.4g clients, web interface, etc) is all still working fine. But the entire 5g radio is just "gone" with no ssid seen by any of the devices. Nothing odd in the logs.

The last time it happened, I adjusted a few things... Mainly changing mode from N/AC to N-Only with fixed 40Mhz width on 5g. I hate crippling it that way, but speed isn't helpful if it isn't stable. So far, everything is stable - but it's only been 52 hours so too early to tell if that made a difference. I sort of hope it is something else, because I want to re-enable AC.

 

[Kevin K]

Fudge. The issue is back. I'm still using factory firmware. 5 GHz simply vanished 4 times in a 24-hour period. I made no changes in the week leading up to the failures. 5 GHz can be brought back to life by making a change to 5 GHz config and applying it or by restarting the router. 2.4 is reliable. 5 is unreliable on the 88u. Sadly, I'm past my Amazon return period.

 

[ScottW]

Very strange you can have stable 5Ghz for weeks, then have it fail 4x in 24hr with no changes in settings.

After the 2 failures I had, each about 3 days apart, I changed settings to limit 5Ghz to N-only (no AC) and was stable for a week. Decided to turn AC back on to see if the problem would return, and have been stable for nearly two weeks.

Based on all the reports, the failures seem pretty random -- and not related to any specific setting. Hopefully it is a driver issue that will eventually be fixed, and not a hardware problem.

 

[Kevin K]

If I can figure out how, I may write a watchdog to restart 5GHz WiFi if no client is visible for 60 seconds. (I have clients which should be visible 24x7.)

If I can't make it stable, I'm going to write off the ~$300 and run over it with my car!

A user on Amazon suggested disabling Airtime Fairness, so I've disabled that too.

ASUS support responded to my negative Amazon review with:

• Disable 'Smart connect'. (It is already off.)
• Wireless -> General -> 5GHz -> Select 'Legacy' or 'N only'. (I set it to N only.)
  
• Change channel bandwidth to '20 MHz' or '40 MHz'. (I already have it set to 40.)
  
• Wireless -> Professional -> 5GHz -> disable Explicit beamforming and Universal Beamforming. (Already done.)

I suspect that the issue is simply highly intermittent, and that none of the suggested changes actually improves the issue. With a recurrence ranging from 20 seconds to 20 days, it is easy to be convinced that a change 'fixed' it, when you're just hitting a period of random availability.

 

[Kevin K]

Reporting back:
After changing 5 GHz Wireless to "N only", I've been stable for a little over 3 weeks. However, after being up for 3 weeks, it stopped routing between the 2 GHz and the 5 GHz access points. That was cured with a restart.

There's no two ways around it -- this router just isn't ready for prime time.