2.4ghz and 5ghz clients cant communicate with each other

[tbrig1]

Will flash back then and try to remember to report back

 

[uildvek]

What firmware are you running? I thought I might revert to stock firmware and see if the bug persists.

I can’t find anything in the WiFi 6 standards that would explain the behavior so do we have a bug reporting process for Merlin or stock ASUS?

I was running 388.2_2 and have since updated to 3004.388.4. The issue is present on both versions.

 

[uildvek]

Will flash back then and try to remember to report back

Thanks for the testing! It would be great to narrow down whether the bug is in asus' stock firmware.

 

[atkinsom]

Damn this was driving me crazy today until I found this thread. My wife prints from her android phone once in awhile and couldn’t see the printer on the 2.4…my iPhone same thing. Tried a ping utility from the iPhone and no response. Never noticed since we have our systems mostly hard-wired and the issue is not present over Ethernet. Anyway a reboot of the AX86u pro was my final troubleshooting step and everything back to normal. Running latest Merlin as well. I’ll check over the next few days to see if it does the same thing which based on others here is highly likely.

AP isolation is off and running one guest network for ecobee

 

[tbrig1]

Almost 2 days on stock firmware and the communications haven't broken. Probably still too early to conclude this is a bug with Merlin though, will check back in a week or two

 

[tbrig1]

Well that didnt take long. It failed on stock firmware. I reported it to Asus. Hope something comes of it.

 

[Tomik]

the problem just came back after 19 days :-(

 

[atkinsom]

Same here again came back after a few days. Hopefully Asus fixes the issue reported by Tbrig

 

[tbrig1]

So far all ASUS has recommended is disabling Universal and Explicit Beamforming on the 2.4ghz radio. I'm trying that for a few days and then they said they'll escalate to software engineering. I'm surprised this issue isn't more commonly reported.

I will probably start scheduling regular reboots of my router if there's no more progress on this soon.

 

[miker33]

My AX86S also does similar being used as a Mesh node, previous AC86U also was useless with continual wifi issues needing a reboot all the time to clear it for a few days.

 

[tbrig1]

Well now I'm stumped. ASUS support was ready for me to escalate to engineering but first they had me update to latest stock firmware and setup totally from scratch. I've been up for close to 6 days now with no issue. I'm running 3.0.0.4.388_24198 which says it was released on November 11th. Maybe it's fixed now?

 

[sfx2000]

I have an Asus RT-AX86U Pro running 3004.388.4. I've configured 2 SSIDs a 5ghz one with SSID names formatted like this: WIFI_5G and WIFI.

Let's go back to basics - SSID's define a WLAN, so two different SSID's (1 for 2.4, the other for 5) says to the client, these are two different and distinct networks.

Use a common SSID, and see if things change...

 

[tbrig1]

Why would that be the case when the underlying IP network is the same? There's no east/west segmentation so I wouldn't expect access over a different radio frequency to matter.

At any rate, the config finally failed again and I've uploaded the config to ASUS for analysis.

 

[sc00bie]

Why would that be the case when the underlying IP network is the same? There's no east/west segmentation so I wouldn't expect access over a different radio frequency to matter.

At any rate, the config finally failed again and I've uploaded the config to ASUS for analysis.

Have you found a solution? I have the same problem. I cannot ping devices on 2.4Ghz from laptop connected to 5Ghz SSID. I've seen this on the stock Asus firmware, as well as Merlin firmware. I'm currently on merlin 3004.388.5 RT-AX86U Pro

 

[glens]

Let's go back to basics - SSID's define a WLAN, so two different SSID's (1 for 2.4, the other for 5) says to the client, these are two different and distinct networks.

Use a common SSID, and see if things change...

Well, yeah. But on the back end, whether AP, node, or router, if they all arrive on the same network segment it /should/ be a non-issue. IP addresses are what it's all about, in the end. I've had no trouble whatsoever to this point communicating with clients on differing SSIDs / bands within the same network.

 

[bennor]

Have you found a solution? I have the same problem. I cannot ping devices on 2.4Ghz from laptop connected to 5Ghz SSID. I've seen this on the stock Asus firmware, as well as Merlin firmware. I'm currently on merlin 3004.388.5 RT-AX86U Pro

No issues with 2.4Ghz and 5Ghz main LAN WiFi clients pinging each other on a RT-AX86U Pro running 3004.388.5. Both WiFi clients are getting an IP address from the main LAN IP address pool. I am not using Smart Connect, each main WiFi SSID has it's own name.
Couple of things to check. Ensure the WiFi client device's firewall, if it has one, isn't blocking local connections. For example I have to disable the Norton firewall on a WiFi PC to get response pings from it (haven't bothered to fix that Norton software firewall to allow ping replies to local network clients yet). And check on the router GUI Wireless > Professional tab that Set AP Isolated isn't enabled. PS:
[Wireless Router] How to Set up AP Isolated feature?

What is AP Isolated feature?

When this feature is enabled, wireless clients or devices will not be able to communicate with each other. You may want to utilize this feature if you have many guests frequently using your wireless network.

 

[AlanD]

I also have a similar problem, using Merlin 3004.388.5 firmware on a recently acquired RT-AX86U Pro.

I upgraded from an RT-AX86U to an RT-AX86U Pro several weeks ago.

The issue was evident when I was unable to print to the 2.4Ghz networked printer from my laptop, I noticed that I cannot ping any of my 2.4GHz devices from my 5GHz connected laptop. I could only ping devices that were connected to the 5GHz SSID. The router can see all devices.

Solution for me is on my laptop; change to the 2.4GHz SSID and then back to the 5GHz SSID and I can then see all the 2.4GHz devices.

I was not seeing this issue at all on the RT-AX86U. I've had a look at the system logs and cannot see anything of interest. The router settings were reset to factory defaults after upgrading to Merlin.

I thought maybe the Group Key Rotation Interval was the culprit, but I'm still seeing this issue when this is set to 0 (Off) or 3600.

I don't have another laptop/PC to test. but from my iPhone, which is connected to the 5GHz SSID, I have no issues accessing the printer, but this 5GHz WiFi connection is regularly reset when the iPhone goes to sleep.

 

[glens]

As a touch-point, I've got XT8s on their latest beta and a GT-AX6000 also on its latest pre-release. Just checked and 5GHz clients on each ping 2.4GHz stuff just fine. Everything's been up for days.

 

[tbrig1]

Hey all,
ASUS support kind of kicked my ticket around and stopped responding after awhile. My recourse until this bug is fixed has been to use the reboot scheduler to reboot my router every couple of days when I know no one will care. It's worked out for me although I'd prefer not to reboot if not needed.

 

[TheLyppardMan]

I also have a similar problem, using Merlin 3004.388.5 firmware on a recently acquired RT-AX86U Pro.

I upgraded from an RT-AX86U to an RT-AX86U Pro several weeks ago.

The issue was evident when I was unable to print to the 2.4Ghz networked printer from my laptop, I noticed that I cannot ping any of my 2.4GHz devices from my 5GHz connected laptop. I could only ping devices that were connected to the 5GHz SSID. The router can see all devices.

Solution for me is on my laptop; change to the 2.4GHz SSID and then back to the 5GHz SSID and I can then see all the 2.4GHz devices.

I was not seeing this issue at all on the RT-AX86U. I've had a look at the system logs and cannot see anything of interest. The router settings were reset to factory defaults after upgrading to Merlin.

I thought maybe the Group Key Rotation Interval was the culprit, but I'm still seeing this issue when this is set to 0 (Off) or 3600.

I don't have another laptop/PC to test. but from my iPhone, which is connected to the 5GHz SSID, I have no issues accessing the printer, but this 5GHz WiFi connection is regularly reset when the iPhone goes to sleep.

I have the opposite situation inasmuch as I can't print to my Canon Pixma TS8350a printer (which is on the 5 GHz network) from any devices that happen to be on the 2.4 GHz network. It's not a problem for me though, because all the devices that need to be able to print are connected to the 5 GHz band, but it does confirm that there is a problem with communication between the networks.