[SurprisedItWorks]

Users zyxx and dplotz (and maybe others) have reported frequent "zero signal" issues on the Linksys MR7350 with recent builds, with the last build seemingly free of this possibly being 61848. I'm seeing this now in 62606, the last build before a major kernel change. The problem is occasionally reported for other routers as well.

What happens in my router is that signal and noise both show as -109 dBm in the GUI, so 0 dB SNR, even if the wifi client is a foot from the router. It's intermittent. I may not see it for days, then one day it's there and I can't seem to get rid of it even with reboots, power cycling, etc.

Has anyone found a workaround? Or a particular wifi setting at issue?

If not, and if you have this problem, let's compare wifi settings, say for 5G (for now). Too many settings to list by hand, so let's try a brute-force approach. Just ssh into the CLI and do

[gitto]

Exactly which page in the GUI are you seeing the -109dBm?
I'm on 62890 and everything seems to be working well on my MR7350 at the moment.
Admittedly I have no idea what I'm doing so things are kept pretty simple.

GUI /Status_Wireless.asp

MAC Address IF Uptime TXRate RXRate Info---- Signal Noise SNR Signal Quality
MAC xxxA5 wlan0 2 days, 8:37:41 5.2M 117.0M VHT80 -91 -106 15 18%
MAC xxx04 wlan1 1:18:59 5.2M 137.6M HE20 -73 -100 27 54%
MAC xxxB6 wlan1 6 days, 13:37:42 5.2M 58.5M HT20 -73 -100 27 54%

[Zyxx]

@SurprisedItWorks:

Currently the MR7350 is in the shelves.
Redid its config so often/nvram erase that I can say it happens with stock settings.

Since DTIM 2 was nasty with some tasmota devices of mine, I set it to 1 for 2.4GHz wireless.
It happened with and without VAPs with mode set to default, mixed or ac/ax/n mixed.

As you observed it worked days without problem and then needed like 3 restarts since 0dBm issue was hindering one band or the other.

Compared to the Dynalink which is in charge now, the 0 dBm issue happened like 10 times a week for the MR7350 and like one time every two months on Dynalink.
With it not appearing on the Dynalink at all the last weeks.
(the Dynalink sometimes lost connectivity after midnight, current build does not seem to have this quirk though).

[Alozaros]

wlan0_regdomai=UNITED_STATES ---> this one has a typo ? N missing ?? just saying..

wlan0_regdomai=UNITED_STATES
wlan0_regdomain=UNITED_KINGDOM

[gitto]

Could that be because it can't have 2 of the same name 'wlan0_regdomain'?

[SurprisedItWorks]

Hi gitto... the -109 dBm refers to GUI>Status>SysInfo, the wifi section. Lots of differences in our settings. You say you haven't seen the problem? I'd follow your lead and go for the same build, but I'm terrified of facing the iptables demise, given my many scripts that use iptables commands. Anyway, I'm going to have to think carefully on what I should try next, esp in light of comments from zyxx above about all he's tried!

Zyxx, I also run a Dynalink as my main router and likewise have hit the zero-signal thing only rarely with it, months apart, and it's never been a serious problem. Have Dynalinks running at two of my kids' houses also, and I've never needed to intervene there on account of this problem. They know to reboot if things ever get too weird.

[gitto]

@Surprised
I don't use IPTables (for me, keep it simple stupid).

My GUI hasn't got /Status/SysInfo and my Syslogd is disabled (not sure if I did that or if that was default).
I did have problems with a couple of the previous builds but mostly they have been ok.
In the last 4 months, the following builds have also worked well for me.
62606
62324
62192
62170
62036

Any settings or comparisons you would like to make - please do let me know.

[SurprisedItWorks]

[gitto]

Got the Sysinfo page up now. Didn't know it existed. Just happy things work when they work as each time I 'fix things', things tends to break.
It doesn't have any other info that wasn't in the other pages - although admittedly it is nice and concise there.

Which box exactly does your -109dBm relate to.
If it is in the 'wireless' box, most of my devices have -106 or -101 noise (no units mentioned) and the SNR seems to be consistent with the Signal and Signal Quality columns. (Distance from router)
(See my previous post with the GUI /Status_Wireless.asp)

I think you would have to try starting from scratch with a basic setup to see if your box does have a problem with DDWRT or if it is your souping up - and then whereabouts in your bling the problem lies - if that is where it is.
Save the config so you can get back to where you are now, try a factory DDWRT then one of the more recent updates and try just basic settings to get you up and running.

Still happy to help but think you might be flogging a dead horse without trying basics first.
A bit like trying to fix a network printer that doesn't seem to be working without disabling the local firewall first - to test. Er hum.

[dplotz]

Late to the party, but here are my settings:

[SurprisedItWorks]

gitto and dplotz, thanks for your settings data. Looks like there are massive numbers of differences between mine and each of yours and also between each of yours and the other's. So the whole approach is looking like a dead end.

gitto... re starting with a reset, etc. The current problem is that I can't get the problem to show again. I had one bad day where the problem was there through several reboots and power cycles, but since then everything has worked fine. It needs to be less intermittent if I'm going to have any shot at chasing it down! So for now I'm going back into observer mode.

And I think I'll go ahead and put 62606 on my Dynalink to see how it looks there. That one's a lot more important in my world.

[gitto]

Well - I'll be around for some time so if you do need to troubleshoot post back. Hope you don't need to though.
Good luck

[SurprisedItWorks]

I finally have another zero-signal device showing in the wifi section. Signal and noise are both shown at -109 dBm, which I am guessing is a minimum for this system. The RX RATE is showing as zero. The connected device is an iPhone 14, and somewhat curiously, it shows a maximum signal strength - three arcs - as is appropriate where it is, less than a meter from the router. I have music streaming just fine through this supposedly horrible connection. The dd-wrt GUI does show a substantial TX RATE, hundreds of Mbps, but even a simple streaming app is going to have some amount of two-way traffic. So the GUI is just wrong when it implies this is a totally broken connection.

So that raises the question: are our worries re this problem warranted? Is it a problem with connection or a problem with display of connection data?

[gitto]

If all your wifi devices work on both 2.4 and 5gHz, then personally I wouldn't really care what the gui shows.
But that is because I spent years caring about stuff that didn't seem to matter and eventually saw the light.
It is annoying if you want to benchmark (but see lines 1 and 2 above) .




If you still want to troubleshoot though and want to compare settings/gui, post back. Happy to play.

[SurprisedItWorks]

Well, it happened again. And the problem is real, not just one of reporting. Could not connect devices (5G), at least not with any significant throughput/reliability. The syslog since boot a few hours earlier had over 1600 lines of "user.err : [ath11k_watchdog] : zero signal issue detected on interface blah" spread over the only two interfaces tried, both VAPs. Finally gave up and rebooted. Came up OK. Accidentally rebooted again. Came up with the problem. Rebooted a third time and all was OK. Two scheduled overnight reboots since, and all is OK. All these are soft reboots... no power cycling.

This is all on my daughter's router on the opposite US coast. She's a very light user with a slow ISP (100 Mbps symmetric fiber), so load was not a factor. (I manage the router remotely using key-authenticated ssh through VPN port forwarding.) My early reports in this thread were on a different MR7350, one here beside me, also lightly loaded but getting internet via station-mode 2G wifi.

At this point my intention is to watch and wait. If it's sufficiently infrequent, we'll just put up with it by rebooting when needed, though I'd probably move her to a Dynalink if I could get another one. Unfortunately, the Dynalink is turning out to have had a very short dd-wrt history, with the router disappearing from the market just after dd-wrt compatibility became a thing.