Desktop has no internet, everything else has , but rebooting router fixes it

[routerq]

Issue: Desktop not having internet but connected to router via Media bridge, all other devices in house have internet. Internet starts working after router is rebooted.
Everything has been fine till now last few weeks. No update to HW or SW or FW has been made.

Setup:
Asus RT-AX86U Pro as Main Router (FW 3.0.0.6.102_34349)
Asus RT-AC86U as Media Bridge connected to main router over 5ghz WiFi ssid
Desktop connected to Media Bridge over 1Gbps LAN
Desktop has a WiFi dongle that can also connect to Main router over the same 5Ghz WiFi ssid
I shutdown the desktop at night and in morning it auto boots/starts
2 Pi Zero W running Pi Hole and Ad Guard Home as DNS connected to Main Router

Detailed Issue:
For last several days, sometimes in the morning, I don't have internet on my Desktop. I am able to connect to the router, the Pi Zero W but no internet. All other devices in home have internet.
Rebooting the Desktop, or the Media Bridge has no effect.
Then I reboot the main router and I have internet.

Today I further experimented.
Connected the WiFi dongle to Main Router and ran speed test. The speed test ran, but the channel it was using was the Ethernet/Media Bridge.
Disconnected the WiFi dongle, no internet / no speed test.
Connected WiFi dongle, ran speed test, again the channel used was the Ethernet/Media Bridge.
Rebooted Desktop, Rebooted Media Bridge (also updated it to latest Asus FW), Removed the wifi dongle, removed the high power BT Dongle. No improvement.
Rebooted Main Router and i now have internet at full speed.


My Guess: Some how the Desktop is not getting DNS resolution. But I am able to log into the Pi Holes from my Desktop, so the connectivity to the PiHole is there.

Thoughts and Tips on what to check ?

Update: 26 July
Issue happened again.

Desktop has correct Pi Hole DNS. No internet
Unable to Ping the Pi Hole or Ad Guard IP
Disabled all other network adapters, rebooted desktop, no internet.
Also, not able to connect to Pi Hole and Ad Guard devices, Ping to them fails. Web GUI connection also fails.
Checked with Tablet on same WiFi SSD, same DNS, it has internet
Changed DNS to public DNS, flushed and renewed DNS on Desktop, We have internet.
Changed DNS to PiHole DNS, flushed and renewed DNS on Desktop, No internet.
Rebooted the router, and Internet is working.

Somehow for the desktop is not able to connect to the PiHole.
NOTE: Desktop / Media bridge are on the Main 5ghz WiFi, Pi Hole on the Main 2.4Ghz WiFi

Have to check moving the Media Bridge to the 2.4Ghz network next time. Forgot it this time.
Have to check Pi Hole VNC connection, next time.

 

[OzarkEdge]

Sounds like a fragile network setup to me but I'm not familiar with all the parts.

Maybe the AC86U 5.0 radio is dying like they do... weird things happen when hardware starts to die. Perhaps wire the desktop to the AX86U and see how it runs with out the media bridge in the mix... or switch the media bridge to use the 2.4 WLAN to test, if that is configurable.

Maybe the desktop with two network interfaces... one a dongle... is confused.

OE

 

[ColinTaylor]

My Guess: Some how the Desktop is not getting DNS resolution.

That would be my first guess as well. I would remove the dongle completely to reduce the number of variables. Then, after rebooting the PC and the problem appearing check what DNS servers your PC is using with ipconfig /all

 

[routerq]

Sounds like a fragile network setup to me but I'm not familiar with all the parts.

Maybe the AC86U 5.0 radio is dying like they do... weird things happen when hardware starts to die. Perhaps wire the desktop to the AX86U and see how it runs with out the media bridge in the mix... or switch the media bridge to use the 2.4 WLAN to test, if that is configurable.

Maybe the desktop with two network interfaces... one a dongle... is confused.

OE

I have removed the dongle and will try the 2.4Ghz next time this happens.

But why would rebooting the AX86U Pro fix the issue of the AC86U?

 

[routerq]

That would be my first guess as well. I would remove the dongle completely to reduce the number of variables. Then, after rebooting the PC and the problem appearing check what DNS servers your PC is using with ipconfig /all

I have removed the dongle, next time this happens I will check the DNS servers. Thanks for the tip.

 

[OzarkEdge]

But why would rebooting the AX86U Pro fix the issue of the AC86U?

When troubleshooting, I try not to project too much so as not to overlook the trouble... I may think it, but I try not to let uncertain presumptions get in the way of finding the issue. For example, here you want an explanation for an unproven premise. It's a reasonable ask... you may be right... except we do know that the issue is not yet fixed.

How old is the desktop? Back in the day I use to have trouble when enabling more than one network interface at a time on the same machine... but I have not experienced this on more modern PCs. You may have a current PC, but you have a dongle that may be older and/or may not integrate very well, so it could be suspect.

When you installed 3.0.0.6.102_34349 on the AX86U Pro, did you Reset and configure from scratch? I normally do but I did not since it was a minor update. Then eventually something went south that disrupted roaming... connects, reconnects, and broken streaming. I twiddled with Roaming and Smart Connect and in the process removed and added back the AX86U Pro node (a Reset). I have not seen the problem since... back to solid use while roaming.

OE

 

[bennor]

But why would rebooting the AX86U Pro fix the issue of the AC86U?

Because the issue may not ultimately be with the RT-AC86U that is configured as a media bridge, the issue may be on the main router (the RT-AX86U Pro).
You have indicated that you are running two Pi Zero W Pi Hole devices along with and Ad Guard Home for local network DNS. If so, it is possible you have a configuration issue depending on how you have things configured on the main router for Pi-Hole and Ad Guard Home. You may want to consider running either Pi-Hole OR Ad Guard Home, not both at the same time.

One troubleshooting step would be to remove the Pi-Holes and Ad Guard Home as the local DNS resolvers and use public DNS servers and test if the issue returns or occurs.

 

[routerq]

Because the issue may not ultimately be with the RT-AC86U that is configured as a media bridge, the issue may be on the main router (the RT-AX86U Pro).
You have indicated that you are running two Pi Zero W Pi Hole devices along with and Ad Guard Home for local network DNS. If so, it is possible you have a configuration issue depending on how you have things configured on the main router for Pi-Hole and Ad Guard Home. You may want to consider running either Pi-Hole OR Ad Guard Home, not both at the same time.

One troubleshooting step would be to remove the Pi-Holes and Ad Guard Home as the local DNS resolvers and use public DNS servers and test if the issue returns or occurs.

Thanks for the inputs.

The setup has been running flawlessly for like few months.

Pi Zero W 1 runs PiHole as primary DNS, Pi Zero W 2 runs Ad Guard DNS a secondary DNS.

Next time this issue happens, I will use public DNS and see if it solves the issue without main router reboot.

 

[routerq]

When troubleshooting, I try not to project too much so as not to overlook the trouble... I may think it, but I try not to let uncertain presumptions get in the way of finding the issue. For example, here you want an explanation for an unproven premise. It's a reasonable ask... you may be right... except we do know that the issue is not yet fixed.

How old is the desktop? Back in the day I use to have trouble when enabling more than one network interface at a time on the same machine... but I have not experienced this on more modern PCs. You may have a current PC, but you have a dongle that may be older and/or may not integrate very well, so it could be suspect.

When you installed 3.0.0.6.102_34349 on the AX86U Pro, did you Reset and configure from scratch? I normally do but I did not since it was a minor update. Then eventually something went south that disrupted roaming... connects, reconnects, and broken streaming. I twiddled with Roaming and Smart Connect and in the process removed and added back the AX86U Pro node (a Reset). I have not seen the problem since... back to solid use while roaming.

OE

The FW was installed in March when it came out and the setup has been running fine since then. Its only last 1-2 week I noticed this issue. And again its not daily, occasionally.

One the FW was updated, I did the reset and config from scratch.

 

[Marcus Yansen]

Can you try on a different desktop? Or does the issue occur on all desktops/pcs, in case it is a specific device issue, i mean if everything else has but desktop and if windows specially, then i wonder if it could be some underlying windows issue

 

[routerq]

Can you try on a different desktop? Or does the issue occur on all desktops/pcs, in case it is a specific device issue, i mean if everything else has but desktop and if windows specially, then i wonder if it could be some underlying windows issue

My Desktop and My Phone are on the same SSID, phone continued to work.

I did not think of that. You may be on to something. Next time I will try this approach also.

 

[degrub]

Under device manager, disable the additional ethernet/wireless adapters not normally used. Then test.
You can also use the CMD by opening a CMD window and typing ipconfig/all
This will show all the adapters, both physical and software, and their DNS, TCP IP configurations

 

[routerq]

Update: 26 July
Issue happened again.

Desktop has correct Pi Hole DNS. No internet
Unable to Ping the Pi Hole or Ad Guard IP
Disabled all other network adapters, rebooted desktop, no internet.
Checked with Tablet on same WiFi SSD, same DNS, it has internet
Changed DNS to public DNS, flushed and renewed DNS on Desktop, We have internet.
Changed DNS to PiHole DNS, flushed and renewed DNS on Desktop, No internet.
Rebooted the router, and Internet is working.

Somehow for the desktop is not able to connect to the PiHole.
NOTE: Desktop / Media bridge are on the Main 5ghz WiFi, Pi Hole on the Main 2.4Ghz WiFi

Have to check moving the Media Bridge to the 2.4Ghz network next time. Forgot it this time.

 

[OzarkEdge]

Have to check moving the Media Bridge to the 2.4Ghz network next time.

Or remove the suspect AC86U media bridge and wire the desktop (no WiFi dongle) directly to the router... move the desktop close or use a long Ethernet cable... to test.

OE

 

[bennor]

Changed DNS to public DNS, flushed and renewed DNS on Desktop, We have internet.
Changed DNS to PiHole DNS, flushed and renewed DNS on Desktop, No internet.

Is the desktop computer configured to obtain DHCP automatically from the router? Or are you manually configuring the desktop computer's network settings?
Where exactly have you configured the Pi-Hole device's IP on the router? Are you using DNS Director? If so, how is it configured?
Do all network clients, including the Pi-Hole device, have an IP address in the same IP address pool?
On the Pi-Hole settings, how have you configured the Pi-Hole DNS Settings page? As a troubleshooting step, change the Interface Setting to the option: Respond only on interface xxx.

 

[degrub]

All devices are in the same 192.168.xxx. subnet, just to confirm ?
Are you using a Guest network ?

Are the Pis IP addresses statically configured ?

This almost sounds like a setting is getting lost/flipped or a time out is occurring that is specific to the router interface with the wireless bridge. And when the router is rebooted it gets established again correctly.

Try a different switch port on the wireless bridge ?

 

[Marcus Yansen]

My Desktop and My Phone are on the same SSID, phone continued to work.

I did not think of that. You may be on to something. Next time I will try this approach also.

By no means do I possess the advice/info of other posters in this thread - but can i ask if ur willing to try one thing - disbale IPV6 in ur network adaptor(s) used to run your connection. I mean it won't break ur computer either u can just re-enable if it doesn't do anything. I just remembered a friend having a similar issue and maybe this helped resolve it.