Asus AI Mesh Ethernet Backhaul keeps disconnecting

[Rizwan]

Hi All
Despite upgrading my main router from the Asus AC86u to the AX86uPro I still had wifi issues (some of which probably due to Smart Connect)
Anyway today I reset the AC86u and added it as a Node upstairs via an Ethernet Backhaul with the AX86uPro connected to the modem and switch downstairs as the main router
What is driving me nuts is that every few minutes it says "disconnected" and "offline" and then randomly shows it as "great connection"
Throughout the entire time the router (node) is of course always on and ethernet cable plugged in and stable

What are possible culprits please for me to check and resolve?
I have upgraded to the latest firmware (it was on 386_12.4 now 3.0.0.4.386_51967-g1c8687c although I crossed everything that it didnt disconnect during the firmware upgrade!

 

[Rizwan]

Update - I tried to delete it and re-add it and now it wont even see the router when I have connected them directly like I did 1st time

 

[bennor]

Just in case it's needed...
[AiMesh] Can I set up wired connection between AiMesh routers (Ethernet backhaul)?
[AiMesh] What is Ethernet Backhaul Mode/Backhaul Connection Priority in AiMesh System and how to set up in different scenarios?

 

[Rizwan]

Just in case it's needed...
[AiMesh] Can I set up wired connection between AiMesh routers (Ethernet backhaul)?
[AiMesh] What is Ethernet Backhaul Mode/Backhaul Connection Priority in AiMesh System and how to set up in different scenarios?

Yes I had put this setting in place
Hence even more perplexed why it kept disconnecting every few minutes then reconnecting with "great" connection

 

[bbunge]

Sometimes with an AC class router you need to bring the node into the same space as the router and set it up over WIFI. Make sure the node is factory reset. Turn off Ethernet Backhaul on the router. Set the router to use the Dual Band SmartConnect, the 2.4 GHz to 20 MHz Auto Channel, the 5 GHz to 80 MHz Auto Channel no DFS. As your AC86U only does 80 MHz there is no reason to push anything higher and 80 MHz will give you better 5 GHz range. Get the node set up on WIFI then connect the Ethernet. Use port 1 on the router and the WAN port on the AC86U for the Ethernet backhaul. You may be best with not enabling the AiMesh Ethernet backhaul and leave the other AiMesh settings at default. Others may say my recommendations are wrong but at least give it a try. Oh, if you are trying Merlin on the AX86U Pro do not use the beta. I also recommend Asus firmware on the router.
EDIT: Make sure WPS is enabled on the router for AiMesh setup.

 

[Rizwan]

Sometimes with an AC class router you need to bring the node into the same space as the router and set it up over WIFI. Make sure the node is factory reset. Turn off Ethernet Backhaul on the router. Set the router to use the Dual Band SmartConnect, the 2.4 GHz to 20 MHz Auto Channel, the 5 GHz to 80 MHz Auto Channel no DFS. As your AC86U only does 80 MHz there is no reason to push anything higher and 80 MHz will give you better 5 GHz range. Get the node set up on WIFI then connect the Ethernet. Use port 1 on the router and the WAN port on the AC86U for the Ethernet backhaul. You may be best with not enabling the AiMesh Ethernet backhaul and leave the other AiMesh settings at default. Others may say my recommendations are wrong but at least give it a try. Oh, if you are trying Merlin on the AX86U Pro do not use the beta. I also recommend Asus firmware on the router.
EDIT: Make sure WPS is enabled on the router for AiMesh setup.

Those are indeed all the wifi settings already

I thought you had to connect with Ethernet if you wanted to work via ethernet Backhaul otherwise it would prioritise WifiMesh because of the way it set up the node?

Ive clearly misremembered that

Mind you right now im struggling to get it to see the router again to add back as a node
Read something that it might be the router retains the mac of the node-router hence wont add it again so I need to first delete it from the device list (something like that) ?

 

[bbunge]

Those are indeed all the wifi settings already

I thought you had to connect with Ethernet if you wanted to work via ethernet Backhaul otherwise it would prioritise WifiMesh because of the way it set up the node?

Ive clearly misremembered that

Mind you right now im struggling to get it to see the router again to add back as a node
Read something that it might be the router retains the mac of the node-router hence wont add it again so I need to first delete it from the device list (something like that) ?

Failing all else a factory reset of both devices works wonders!

 

[Rizwan]

Failing all else a factory reset of both devices works wonders!

Update.
Factory reset of the AC86u and unplugging Ax-86u, deleting entry of ac86 from client list of Router and it now works and is stable

Albeit strangely it now calls the connection "okay" (and wifi speeds aren't great but at least we have stable WiFi now in areas we had none) whereas when it was dropping out it was flitting between "great" and disconnected (i removed an intervening switch between node and Ethernet point and used node as local switch

When i have energy i might try a different Ethernet cable to the node from the point in the room to see if that helps

 

[drabisan]

Although I would assume it's a wide agreement AC86U was one of the best work horses Asus could dream for, it's not ideal at all to combine an AX with an AC. Different capabilites, different modulation, clients will struggle. More or less visible.
Connection Quality should be Great if you have decent cables. Doen't take expensive cables to have a 1G link. You should see link speed in the WebUI.
Did you check the logs just before it was disconnecting? Were there any hints?

 

[Rizwan]

Although I would assume it's a wide agreement AC86U was one of the best work horses Asus could dream for, it's not ideal at all to combine an AX with an AC. Different capabilites, different modulation, clients will struggle. More or less visible.
Connection Quality should be Great if you have decent cables. Doen't take expensive cables to have a 1G link. You should see link speed in the WebUI.
Did you check the logs just before it was disconnecting? Were there any hints?

All good questions! I didnt take the logs of the "before" as I just took the nuclear option of factory reset of the AC and redo
As it happens you prompted me to look a little deeper and I spotted that actually the WAN light was not on the AC now and the uplink was 5GHz wifi
A trip up to the loft showed the switch there wasnt showing a light for the ethernet point in the bedroom so I did some cable jiggling
Now it shows "normal" and ethernet uplink but only at 100mb which I suspect is a cable issue between switch in loft and the between socket as other connections from the same switch are giga
Wifi speeds upstairs also improved from 20mb to 70mb as a consequence but obviously should be much better this way

Will need to muster the energy to redo that cable and get my crimping tools out etc when I have more spare time but at least for now I have made a little more progress

I still am none the wiser though how it was showing "Great" connection (then dropping out to disconnected) with the same topology before the AC reset when in fact there was another switch in the way of the router (socket, switch AC node with satellite box plugged into switch vs now socket direct to WAN on node with satellite box plugged into the AC node and switch in room removed)

 

[degrub]

dirt/film/corrosion at the socket and connector contact.

 

[Rizwan]

dirt/film/corrosion at the socket and connector contact.

Makes sense
It was very grubby in loft
Will try to clean both ends and see if it improves

As a test I also tried a different wire from socket to AC but no change
I suspect the important part is the connector contact in loft

Appreciate the continued advice