2.4ghz and 5ghz clients cant communicate with each other

[tbrig1]

Oh, I also took a packet capture and just basically saw broadcasts for the 2.4ghz client with no response from the router. ARP table on router has both source and destination MAC’s present.

 

[tbrig1]

Took a diff of my show nvram and see that when the wireless stops working the following values are different.

This is working config vs failed config:
- obd_allow_scan=0 vs not present in nvram
- wl1_dpp_status=15 vs wl1_dpp_status=16
- wl_radio=0 vs wl_radio=1

I tried looking at the source of the code in merlin's github repo but I don't understand these values yet. Not sure if the next time it fails if I can just set these to what they are when the router is working and test communication.

 

[Dotty2913]

I am having the same problem. My ASUS laptop (on 5Ghz wifi) will not communicate with our Canon Printer which is on 2.4Ghz and same with another device on our network. I submitted a support request with ASUS and received an extensive email with initial steps to try with settings. This worked (like others in this forum) for a short time then reverted to non-communication between bands again. The next steps they offered were to hard reset, or go back to previous firmware. I have tried many things and find it frustrating that I have to move my ASUS laptop to the 2.4ghz band to simply print a document. Wondering if anyone has any updates or knows of anything else to try ?? I am using ASUS firmware

 

[tbrig1]

I’ve had to settle on using the reboot scheduler in the administration menu and rebooting the router overnight, weekly when i know no one is using it.

ASUS wasn’t helpful when i raised this either and it seems they either don’t know how to fix it or don’t care.

 

[uildvek]

Yeah I basically resorted to running a SOCKS5 proxy server on my NAS which is connected via ethernet (as ethernet connected devices can always access all clients it seems) and using the proxy on my phone and computer so they can access 2.4GHz clients.

 

[tbrig1]

Right that’s my experience. Anything connected to the switch ports, even another switch connected to those ports, continues to work. It’s really just the internal communication between the two bands.

 

[mlord]

Some of the 2.4GHz IoT clients here have coloured LED indicators for status. Every now and then I notice some of them blinking the "no WiFi connection" indication. So here at least, it's not a 2.4 <--> 5GHz issue, but rather just something on 2.4GHz periodically causes them to lose connection. They do recover eventually, hours later. A router reboot seems to bring them all back immediately.

I'm going to try the suggestion of limiting 2.4GHz to 20MHz channel width.

 

[Shenanigans]

I have the same issue with my RT-AX86U Pro. Is there still no reliable fix for this? This is really annoying. Can anyone recommend any router that is as good as the RT-AX86U Pro and doesn't have this problem?

 

[AlanD]

The only reliable way I can fix this is to reboot the router. I do as tbrig1 does...scheduled reboot every morning at 0300. Fixes the 2.4 / 5GHz bridging issue within a minute.

 

[bennor]

@Shenanigans and @AlanD, Are you having the issue on the Guest Network WiFi or having the issue on the main LAN WiFi?

Personally, I do not appear to be having any of the issues with main LAN WiFi 2.4Ghz and 5Ghz clients seeing and accessing each other on a RT-AX86U Pro running 3004.388.7 with YazFi and YazDHCP running on the router. Have a headless Raspberry Pi Zero W connected to main LAN 2.4Ghz WiFi that can ping a Windows 11 PC connected to main LAN 5Ghz WiFi. And that main LAN 5Ghz WiFi Windows PC has no issues pinging, or using SSH or accessing the Pi Zero's Pi-Hole GUI page using a web browser. I don't have to restart the router or perform any other actions to reset the router WiFi. Both devices can access each other. Same goes for accessing a HP OfficeJet printer connected to main LAN 2.4Ghz WiFi. Windows 11 PC on 5Ghz main LAN WiFi can access and print/scan to/from that 2.4Ghz main LAN WiFi connected HP OfficeJet printer without issue.

Some additional notes about the RT-AX86U Pro router settings I'm using:
WPS is disabled (set to OFF)
Smart Connect for the WiFi is disabled (set to OFF).
Each WiFi band has a unique SSID.
Authentication Method on both WiFi bands is set to WPA2-Personal.
I am not using AiMesh and do not have any down stream AP nodes or down stream WiFi extenders.
I currently do not have any additional scripts beyond YazDHCP and YazFi running.
In the past I've done a hard factory reset and manual configuration (no saved router.cfg import) when updating the Merlin firmware.
On the HP OfficeJet printer, Wi-Fi Direct is disabled (turned OFF)

 

[Shenanigans]

0300. Fixes the 2.4 / 5GHz bridging issue within a minute.

I upgraded to the newest firmare 3 hours ago, which obisously leads to a reboot. But the problem is already there again. Will still try to reboot at night, maybe it will help...
Update: So I do a reboot of the rooter now every night at 2am and it actually seems to fix the issue. Thanks!

 

[mlord]

I'm going to try the suggestion of limiting 2.4GHz to 20MHz channel width.

The issue here went away after I made that change. All good now.

 

[tbrig1]

I have my 2.4ghz set to 20mhz bands as that is the only way to deploy 2.4ghz with non-overlapping channels. It hasn’t made a difference for me for this issue.

 

[AlanD]

I just had a scheduled reboot at 03:00 and the RT-86U Pro Router failed to boot. Fantastic. Had to get my 86 year old mother to cycle the power manually. That was a 28 minute phone call to explain what to do.

I love this router....NOT !

 

[atkinsom]

I just had a scheduled reboot at 03:00 and the RT-86U Pro Router failed to boot. Fantastic. Had to get my 86 year old mother to cycle the power manually. That was a 28 minute phone call to explain what to do.

I love this router....NOT !

Dude you just made my day!! I was seriously ROFL as your description is exactly what I go through with my own 82 year old mom!!! It’s truly painful when her router acts up

 

[Chulamin]

Hi. New to this forum. At least I found this thread before I tore apart my system. I too have tried everything. I even have an open ticket with Asus.
One thing I did discover. The AX86U replaced an AC68U that I set up as a mesh node. If I put all my 2.4ghz devices on the AC68U node, everything works. If I leave them on the AX86U then they break. I'm not sure what to make of it.

 

[Tech9]

If I put all my 2.4ghz devices on the AC68U node, everything works. If I leave them on the AX86U then they break.

Your issue is perhaps different. Your AX-class router may not be as compatible as AC-class to all your 2.4GHz devices. See this:

[Wireless Router] How to improve compatibility of IoT device with ASUS WiFi 6(802.11 ax) router? | Official Support | ASUS Global

 

[Chulamin]

I already went through that. No change. If those 2.4ghz devices are connected to the AX86U they don't connect to 5Ghz devices. If I bind them to the AC68U mesh node, they work perfectly. The problem is elsewhere.

 

[uildvek]

It looks like I was able to resolve this issue by disabling guest network 1 and using guest network 2 instead. Been up for 2 weeks with no issues so far.

 

[latency95]

on latest asus merlin. was trying to figure out why one of my ip cams was not working from some phones.

it is not just an issue of bridging from 2.4 ghz to 5ghz wifi issues. it is more nuanced and probably why not everyone sees it


wired port <-> 2.4 ghz GOOD
wired port <-> 5 ghz GOOD
2.4 ghz <-> 5 ghz via WIFI 6 (ax) BAD
2.4 ghz <-> 5 ghz via WIFI 5 (ac) GOOD
2.4 ghz <-> 5 ghz via WIFI N untested.

I have not tried (N) yet on 5ghz to test. My 5Ghz is set to N/AC/AX mixed.
Something different about connections on 5ghz AC is letting it get to my 2.4 ghz devices but not the 5ghz AX.
There appears to be some distinction here.