ASUS AX68U 5GHz Band Dropping / Disappearing

[OzarkEdge]

I recently bought the AX68U , and am experiencing similar issues with 5 GHz devices disconnecting. It works at maximum for 24-36 hours and the disconnects happen. I tried the changes mentioned above, and disabled those settings, but now the issue has become more frequent. Anyone has any other suggestions?
@salsashark , is your router still working without interruption after those changes?

Thanks.

Are you using 160 MHz on DFS channels?

OE

 

[L4N0]

Are you using 160 MHz on DFS channels?

OE

No, this router does not support DFS or 160 Mhz. I have set it on channel 157.

 

[salsashark]

I recently bought the AX68U , and am experiencing similar issues with 5 GHz devices disconnecting. It works at maximum for 24-36 hours and the disconnects happen. I tried the changes mentioned above, and disabled those settings, but now the issue has become more frequent. Anyone has any other suggestions?
@salsashark , is your router still working without interruption after those changes?

Thanks.

My router dropped once since that post. Changed the Channel Bandwidth from 20 / 40 / 80 MHZ to 40 MHZ and the control channel from Auto to 157.

Has not dropped in 3 days so far.

 

[L4N0]

I tried with 40 MHz channel for a short time, but it cuts the speed in half, so you can't use the full potential of this router. I would not want that to be a permanent solution. Does anyone have an alternative solution or other diagnostic steps? Could the problem be solved by using Merlin firmware instead?

 

[L4N0]

After testing different options, I was able to get more reliability from my AX68U by switching to a lower range of channels (Control Channel 48) and still keeping 20/40/80 MHz mode, which allows devices to connect at 80MHz bandwidth. This has made the 5Ghz disconnects very rare.

 

[Invisible Boy]

For some unknown reason (maybe due to the Canadian regulations), my AC68U & AX11000's 5GHz has the best coverage with channel 149 80MHz (didn't try DFS), and the lower band has much worse coverage at any distance (up to -20dBm). I have repeated the tests many times with identical results. However, my WiFi has never had any disconnect once I finalized the settings (work for both official FW and Merlin). Maybe you can replicate my settings and see if they work for you.

 

[Tech9]

my AC68U & AX11000's 5GHz has the best coverage with channel 149 80MHz

It's going to be different in different Wi-Fi environments. My best throughput channel is 40 @80MHz, for example. Also under Canadian regulations. I have 4x access points and the coverage is about the same on any channel. General recommendation - experiment and find what works best for you.

 

[MotR]

I have exactly the same issue with the AX68 with the latest firmware. 5 ghz wifi disconnects almost immediately and will not return unless rebooted.

I use the AX68 as an AImesh node with the AX86 as the main node. I do not use smart connect, use channel 36 and 80 mhz bandwidth. The AX68 is connected via ethernet to the AX86.

I have reset the AX68 via the WPS method, it does not help. Only thing that works is reverting back to the previous firmware, which is perfectly stable.

 

[Invisible Boy]

From what I have heard, Taiwan excels in electronic engineering but weak on software development. Maybe this is reason that ASUS products (also other brands) have been plagued with buggy firmware.

 

[disjt]

For some unknown reason (maybe due to the Canadian regulations), my AC68U & AX11000's 5GHz has the best coverage with channel 149 80MHz (didn't try DFS), and the lower band has much worse coverage at any distance (up to -20dBm). I have repeated the tests many times with identical results. However, my WiFi has never had any disconnect once I finalized the settings (work for both official FW and Merlin). Maybe you can replicate my settings and see if they work for you.

In Canada, channels 149-165 have a much higher allowable transmit power. See this link for more information. That's 5x the power, or up to 20x with antenna gains. (edit: the 20x is for point-2-point devices, so that excludes our routers)

 

[Invisible Boy]

In Canada, channels 149-165 have a much higher allowable transmit power. See this link for more information. That's 5x the power, or up to 20x with antenna gains. (edit: the 20x is for point-2-point devices, so that excludes our routers)

Thanks again for the reply. You have provided the solid answer that I was looking for in another thread.

 

[zjuljin]

hello, i have same issue here with latest Asuswrt-Merlin 386.4 firmware. disconnect only appear on 5GHz Band, no issue with 2.4GHz.
smart connect is off.
did try to set control channel to a fix value but not change anything

issue seems to appear few days after the firmware update.
never do a factory reset after a firmware update

i think i'm going to try to go back previous firmware (386.3_2)

 

[MrAsusIsBack]

Hi there,
the RT-AX68U has really great performance. But he actually has a problem with the 5Ghz band, I can confirm that too.
I've had it for 6 months and try to use it as a node with the RT-AX86U as the master with every new firmware update.
If you then deactivate the 2.4 GHz band in the node settings, practically nothing works anymore at the RT-AX68U.
Exactly the same issue with the RT-AX55U, but sold because really worse overall performance. All with Ethernet backhaul, of course.
However, the RT-AX58U works perfectly if only the 5Ghz band is activated in the node. I'm still waiting for this problem to be fixed.
I would be happy if someone could confirm this behavior.

Because none of them works properly, I have now bought half the product range. -> Asus has really a good business plan

 

[AlleyCat]

In my experience, Roaming Assistant can cause frequent disconnects if the RSSI is set too high. The default value is -70dBm, which I’ve found to be problematic; -76dBm works better in our situation.

Roaming Assistant seems to cause more problems than it solves, so for testing purposes, you can try disabling Roaming Assistant:

Wireless—>Professional—>Roaming Assistant—>Disable—>Apply

disable RA on both bands (2.4 and 5GHz)

 

[MrAsusIsBack]

Both roaming assistens are off. Problem ist that when you switch of the 2,4Ghz band in Node managemant the 5Ghz Band of 68U is complete "death". The 5GHz LED is on.
The behavoir is always exact the same with RT-68U as node. It works only if both radios active. 2.4GHz is not needed because crowded. ONly the Master has 2,4GHz on for some IoT devices.
Especially when the 68U is plug off from power as node and you plug in, the 5Ghz band never came up, but 5gHz led is on. Only 68U has this behaviour. Hopefully ASUS will fix it, support doesn't really interrested in issues like this.

 

[OzarkEdge]

In my experience, Roaming Assistant can cause frequent disconnects if the RSSI is set too high. The default value is -70dBm, which I’ve found to be problematic; -76dBm works better in our situation.

My current approach to using RA is to accept the default -70 dBm RSSI threshold (or closely similar) as a starting point (minimum acceptable signal power for certain connection performance) and then increment the RSSI threshold +x dBm from there until stationary clients boot and connect to the desired node) after first determining the node location that is not "problematic" at -70 dBm. Of course, if node location is not so flexible, then you might accept a weaker signal starting point more negative than -70 dBm (and that impact on connection performance).

That said, I'm getting good results with RA disabled and letting my clients decide when to roam... I think because my nodes are not too close together.

OE

 

[MrAsusIsBack]

In 86U Master, the node management of the 68U shows often this behaviour, it depens how often you switch off/on an radio or unplug the power source. Is this behaviour only in combination with the AX86U???

 

[AlleyCat]

My current approach to using RA is to accept the default -70 dBm RSSI threshold (or closely similar) as a starting point (minimum acceptable signal power for certain connection performance) and then increment the RSSI threshold +x dBm from there until stationary clients boot and connect to the desired node) after first determining the node location that is not "problematic" at -70 dBm. Of course, if node location is not so flexible, then you might accept a weaker signal starting point more negative than -70 dBm (and that impact on connection performance).

That said, I'm getting good results with RA disabled and letting my clients decide when to room... I think because my nodes are not too close together.

OE

I did experiment with various Roaming Assistant thresholds, but some wireless clients frequently disassociated, then immediately reassociated, whenever RA was enabled, so I turned RA off for both bands.

In fact, RA is the only option that I’ve disabled. All other options in Wireless —> Professional are enabled; including Airtime Fairness, Aggregation, WMM No-Ack, Beamforming, OFDMA + MU-MIMO, etc… all options are enabled except for RA.

I also manually selected channel 149 for best performance on the 5GHz band, which does not allow for 160MHz wide channels, I know, but that’s ok in our environment because SNR is much better on the UNII3 channels than UNII2 and UNII1. DFS channels are useless where I live, near a military base with weather radar

I set the 2.4GHz band to Auto and WPA2 authentication for both bands. We only have a couple 2GHz-only devices on our network.

Also, with Asuswrt-Merlin v386.4, disabling 802.11b prevented some wireless devices from connecting, even though they are not 11b devices. I made the mistake of ticking the ‘Disable 11b’ box in Wireless settings, thinking that would tweak performance. It had the opposite effect, and the box cannot be unticked, presumably a bug. The only way to revert 11b to enabled is to SSH into the router and issue these commands.

Here are the wireless settings that work well in our environment:

 

[MotR]

Hi there,
the RT-AX68U has really great performance. But he actually has a problem with the 5Ghz band, I can confirm that too.
I've had it for 6 months and try to use it as a node with the RT-AX86U as the master with every new firmware update.
If you then deactivate the 2.4 GHz band in the node settings, practically nothing works anymore at the RT-AX68U.
Exactly the same issue with the RT-AX55U, but sold because really worse overall performance. All with Ethernet backhaul, of course.
However, the RT-AX58U works perfectly if only the 5Ghz band is activated in the node. I'm still waiting for this problem to be fixed.
I would be happy if someone could confirm this behavior.

Because none of them works properly, I have now bought half the product range. -> Asus has really a good business plan

For me, switching off 2.4 ghz in the node settings of the AX68 does not help, 5 ghz wifi is still not working with firmware 45934. Even downgrading to 42808 did not work any more. Also there 5 ghz was gone (using AImesh).

After that I WPS-reset the AX68 and did a setup as an Access Point. Now 5 ghz worked again. Even after upgrading to 45934 again. I will now wait for a few days and see how 5 ghz behaves. If this does work I will probably hard reset my AX86 too and setup everything new again.

 

[MrAsusIsBack]

Can you please unplug your node from power source once and check if 5GHz is still coming back?