GT-AX6000 AiMesh: clients getting knocked off

[DianaRea]

Hello,

This is my first post here.

I had a ASUS GT-AX6000 wifi router for a few years which worked excellent.
I recently moved to a new place in which the single access point cannot cover the premises.
So I figured that I needed one more ASUS GT-AX6000 to extend the wifi coverage and that AiMesh would probbly be ideal for that.


So now I have two ASUS GT-AX6000 wifi routers. I have CAT6a cable between them.
Both have the Asus Merlin firmware on them version 3004.388.4

I have set these up for AiMesh. The new one being the node, the old one being primary.

Ethernet cable is connected from mesh node's 2.5GbE LAN port to the primary's first 1GbE port.
I have enabled "Ethernet Backhaul Mode".
On the mesh node, I have set it to prefer 2.5GbE LAN for backhaul.

According to the GUI, all seems OK.

However, when I power on the mesh node, the devices using wifi keeps getting disconnected.
At first I thought I had accidentially made a switch loop and that this was what killed the network, but this appears not to be the case because all the ethernet connected devices work just fine.

What seems to happen on the wifi clients is that they are able to connect to the wifi but the OS reports "no internet connectivity".
The clients are a mix of MacOS and Windows.

My network topology is like this:

Internet is provided via fiber modem in "bridge mode".
Fiber modem is connected to WAN port on the primary RT-AX6000.
Primary RT-AX6000 is the default gateway for all the network nodes.

Network configuration is provided via DHCP on a Linux server.
(DHCP is disabled on the primary RT-AX6000)

DNS is provided by two Linux servers. (primary and secondary DNS)
The primary is doing DNS based adfiltering via pihole.


The Primary RT-AX6000 has 4 1GbE LAN ports + 1 2.5GbE LAN port.
The 2.5GbE port is unused.
First 1GbE port is connected to the mesh node RT-AX6000.
Second 1GbE port is connected to an HP 1GbE switch to which all the remaining ethernet devices are connected.


My questions to you are:


1: What may be wrong with my setup causing the wifi to not work when the mesh node is connected? Is this a known problem?

2: Is it a problem that I have the ASUS Merlin firmware on the mesh node? Should I rather have kept it to the vanilla firmware?

3: Any idea how to fix this?

4: Am I approaching this the wrong way? I mean, poor wifi coverage was the reason I even started going down the AiMesh path. But now I start doubting that mesh is even the right approach. Are there better alternatives? I think there are also products like wifi repeaters/wifi extenders. Would they be better suitable here?

 

[DianaRea]

I was thinking that perhaps I should have kept the mesh node on the stock Asus firmware. However, according to the Merlin documentation (https://github.com/RMerl/asuswrt-merlin.ng/wiki/AiMesh), this does not seem to be required.

Asuswrt-Merlin 384.13 adds full support for AiMesh (both as a primary router and as a node). Nodes can run either stock Asus or Asuswrt-Merlin

The docs mention one limitation when using Merlin firmware on node, but this does not seem relevant here:

Nodes running this firmware will have one limitation over running on the stock firmware, which is they will lack the ability to automatically download and install new firmware versions. New firmware availability notification will still work, and the changelog will also be visible through the webui, but you will have to use the node's Upload hyperlink to manually upload any new firmware. Nodes running on the stock firmware will retain their ability to do live updates by using the global Firmware Upgrade button.

So I guess I can ignore that part?



Another thing I found in the documentation:

Note that AiMesh can sometimes be less stable than using a plain router + access point or repeater configuration due to the increased complexity of sharing configuration between the main router and its node(s).

This seems to hint that there might be a better approach than AiMesh.
What is meant by plain router + access point or repeater config?
Does this mean that I just set up two identical wifi configurations?

 

[Tech9]

AiMesh Wiki page was last edited in 2019. Stock firmware for your routers is 3006 base, Asuswrt-Merlin is 3004 base. If you don’t use any of the advanced Asuswrt-Merlin features like VPN Director or Custom Scripts - try stock 3006 on both. It adds SD WAN, user configurable VLAN support, Guest Network Pro, Captive Portal.

 

[DianaRea]

Added screenshot of mesh node config

aimesh config

primary config:

 

[DianaRea]

AiMesh Wiki page was last edited in 2019. Stock firmware for your routers is 3006 base, Asuswrt-Merlin is 3004 base. If you don’t use any of the advanced Asuswrt-Merlin features like VPN Director or Custom Scripts - try stock 3006 on both. It adds SD WAN, user configurable VLAN support, Guest Network Pro, Captive Portal.

I see.
So, I could try loading stock firmware on the mesh node. But I would really hope I could avoid using the stock firmware on the primary... I mean, if I have to, I have to, I guess. But I would really like to avoid.

Am I right that just flashing the mesh node with Asus stock firmware 3006 would not work as primary and node would have to be identical versions?

Could I flash node to stock 3004 firmware? Would this likely fix anything?


I see there is a 3006 version of merlin firmware. Is this not compatible with the GT-AX6000?

 

[Tech9]

Try stock firmware on the node first. There is no 3006 Asuswrt-Merlin for this model at the moment. Don’t flash older firmware versions, the last firmware fixes security issue.

 

[DianaRea]

Try stock firmware on the node first. There is no 3006 Asuswrt-Merlin for this model at the moment. Don’t flash older firmware versions, the last firmware fixes security issue.

Got it. Flashing mesh node with stock 3006 now.

Will report back how it goes...

Waiting a bit with the primary...

 

[DianaRea]

Mesh node is flashed with stock 3006 now. Waiting to see if I get any complaints about this not working

 

[bbunge]

With Ethernet Backhaul mode enabled you do not have to set the other connection priorities.
I have found that leaving the AiMesh settings to their default (Auto) works best for most folks. I have Ethernet Backhaul mode enabled and have turned off WPS in the Wireless settings. I use the 2.5 GB ports to connect the router to node with CAT 5e cable. I do not do this for the bandwidth but just because it is an extra port on the router.
Does not seem to matter which firmware you use on the router or nodes. Many do recommend Asus firmware on the nodes but my testing does not show that is right.

 

[Tech9]

Mesh node is flashed with stock 3006 now.

Many folks around are using Asuswrt-Merlin on main and stock Asuswrt on node(s). There is no real benefit of Asuswrt-Merlin on nodes, there is no routing there, they are Repeater (wireless) or Access Point (wired). If the main goal is AiMesh I would run the same 3006 stock firmware on both. For this router it's newer Asuswrt 5.0 firmware with features not present in Asuswrt-Merlin at the moment. The real benefit of Asuswrt-Merlin is in advanced VPN configurations and Custom Scripts ecosystem. Everything else is available now in stock Asuswrt one way or another. Both firmware versions are stable and secure enough. Keep in mind Asus removed all old firmware versions for your router including 3004 and you may not be able to flash back to Asuswrt-Merlin in GUI. One of the last Asuswrt versions is now minimum required for this model.

 

[OzarkEdge]

Mesh node is flashed with stock 3006 now. Waiting to see if I get any complaints about this not working

Hard Reset the node firmware before adding it from the router webUI.

FW Reset FAQ

Reset button/webUI Restore/node removal clears settings in NVRAM; reboot restores fw defaults from CFE

Hard Reset via WPS button/webUI Restore+Initialize also clears data logged in /jffs partition

Rarely, a new node will not boot right, so be sure to let the network settle and then reboot router followed by node.

I'm also wondering if AiMesh is having issues with your network's DHCP/DNS/gateway arrangement. My preference would be to prove the default AiMesh network with ASUSWRT; then try ASUSWRT-Merlin on the router; then mix in your Linux bits... like you are building a new network, one step at a time.

You will eventually want to have ASUSWRT 5.0 (3.0.0.6.*) on all nodes, with or without ASUSWRT-Merlin... imo.

OE

 

[DianaRea]

OK. Reporting back now. I have tried going with the stock Asus 3006 firmware for a few hours. My kids started complaining that wifi was not working so I ended up shutting the mesh node down for now.... I guess I could try flashing the primary with the stock Asus 3006 firmware as well. However, I am a bit reluctant to do that because 1: I really like the merlin firmware and the UI, and the fact that it is open source; and 2: according to tech9, I might not be able to flash with merlin again

Also, I am not sure if it is even worth trying to flash with stock Asus fw on the primary. Do we have any reason to believe this would fix the issue?

Is it likely that this is a hardware issue? Should I RMA the box?

 

[DianaRea]

With Ethernet Backhaul mode enabled you do not have to set the other connection priorities.
I have found that leaving the AiMesh settings to their default (Auto) works best for most folks. I have Ethernet Backhaul mode enabled and have turned off WPS in the Wireless settings. I use the 2.5 GB ports to connect the router to node with CAT 5e cable. I do not do this for the bandwidth but just because it is an extra port on the router.
Does not seem to matter which firmware you use on the router or nodes. Many do recommend Asus firmware on the nodes but my testing does not show that is right.

Thanks for your response.
I just tried disabling WPS. Although, I would be surprised if this is related at all.

 

[DianaRea]

Many folks around are using Asuswrt-Merlin on main and stock Asuswrt on node(s). There is no real benefit of Asuswrt-Merlin on nodes, there is no routing there, they are Repeater (wireless) or Access Point (wired). If the main goal is AiMesh I would run the same 3006 stock firmware on both. For this router it's newer Asuswrt 5.0 firmware with features not present in Asuswrt-Merlin at the moment. The real benefit of Asuswrt-Merlin is in advanced VPN configurations and Custom Scripts ecosystem. Everything else is available now in stock Asuswrt one way or another. Both firmware versions are stable and secure enough. Keep in mind Asus removed all old firmware versions for your router including 3004 and you may not be able to flash back to Asuswrt-Merlin in GUI. One of the last Asuswrt versions is now minimum required for this model.

> If the main goal is AiMesh I would run the same 3006 stock firmware on both.


It is not. The main goal is to extend the coverage of wifi throughout the house while being transparent to the users. If AiMesh is the right way or not, I am not sure. I assumed this was the best way. But if it is better to do something else, I am all ears! I understand there is also some WDS or Bridge function that allows me to do some repeater mode. Would this be better?
Are there other methods?


> Keep in mind Asus removed all old firmware versions for your router including 3004 and you may not be able to flash back to Asuswrt-Merlin in GUI. One of the last Asuswrt versions is now minimum required for this model.


This concerns me a great deal. I really like the merlin UI and the stock Asus firmware that came on the box was some gamer "ROG" theme that looked similar to a Doom game or something like that.
Not being able to revert makes me anxious.

 

[DianaRea]

Hard Reset the node firmware before adding it from the router webUI.

FW Reset FAQ

Reset button/webUI Restore/node removal clears settings in NVRAM; reboot restores fw defaults from CFE

Hard Reset via WPS button/webUI Restore+Initialize also clears data logged in /jffs partition

Rarely, a new node will not boot right, so be sure to let the network settle and then reboot router followed by node.

I'm also wondering if AiMesh is having issues with your network's DHCP/DNS/gateway arrangement. My preference would be to prove the default AiMesh network with ASUSWRT; then try ASUSWRT-Merlin on the router; then mix in your Linux bits... like you are building a new network, one step at a time.

You will eventually want to have ASUSWRT 5.0 (3.0.0.6.*) on all nodes, with or without ASUSWRT-Merlin... imo.

OE

> Hard Reset the node firmware before adding it from the router webUI.

Well, when I flashed it and rebooted, it automatically came up with the mesh node config, so I guess you raise a good point here that some old config is left over.
So do I just need to hold in the reset button?
I have never used the WPS functionality before. Not sure if I need to do that too?


> I'm also wondering if AiMesh is having issues with your network's DHCP/DNS/gateway arrangement. My preference would be to prove the default AiMesh network with ASUSWRT; then try ASUSWRT-Merlin on the router; then mix in your Linux bits... like you are building a new network, one step at a time.


It is my understanding that the mesh node is entirely on the wifi/link layer and thus should work independently of DHCP/DNS, or am I missing something?


> You will eventually want to have ASUSWRT 5.0 (3.0.0.6.*) on all nodes, with or without ASUSWRT-Merlin... imo.

If I wait, should there come a merlin version 3006 for my router or will this not happen?

Did I bet on the wrong equipment? Should I rather have bought some other router?

 

[bbunge]

I have had issues when the 2.5 GB port is used. Switching to a 1 GB LAN port on the router and the WAN port on the node seemed to "fix" the disconnect issue. Happened regardless of firmware. Do you have a managed switch in between? Is the CAT 6 cable a pre made one or one installed by someone who did not test it?
There is nothing wrong with the Merlin firmware on the router. But it is a good idea to hard reset the node by holding the WPS button while powering on then releasing the WPS button when the power light goes off. Then power cycle.

 

[OzarkEdge]

> Hard Reset the node firmware before adding it from the router webUI.

Well, when I flashed it and rebooted, it automatically came up with the mesh node config, so I guess you raise a good point here that some old config is left over.
So do I just need to hold in the reset button?
I have never used the WPS functionality before. Not sure if I need to do that too?

Be sure to read and understand the links I posted. The firmware default settings belong to the firmware... you must ensure significantly new/different firmware is using its defaults to begin with, not the previous firmware's settings. Hence, install the firmware and reset it to be most sure. Then any troubleshoooting will be more productive.

Nevermind WPS... just confirm it is disabled, if you do not need it. AiMesh uses it to add a wireless-only node if the node is not already wired... regardless of it being enabled or disabled beforehand.

Ethernet Backhaul Mode enabled simply prohibits using wireless backhaul, to not share WiFi between clients and wireless backhaul. If you leave EBM disabled with a wired backhaul and Priority Auto, AiMesh should use the best backhaul... in your case, it could/should be the 2.5Gbps wired backhaul between 2.5GbE ports, and AiMesh should turn OFF its wireless backhaul until needed for failover in the event the wired backhaul fails/gets chewed up by your cat. Lay an eye on port status in the webUI to be sure connectivity is as you wired it and expect. You can also see a wireless backhaul entry with NSS 3 or 4 in the Wireless Log when its ON... should be absent when OFF, when using wired backhaul... if not right, toggle EBM to clear it... a minor glitch I've seen but not your problem here today.

> I'm also wondering if AiMesh is having issues with your network's DHCP/DNS/gateway arrangement. My preference would be to prove the default AiMesh network with ASUSWRT; then try ASUSWRT-Merlin on the router; then mix in your Linux bits... like you are building a new network, one step at a time.

It is my understanding that the mesh node is entirely on the wifi/link layer and thus should work independently of DHCP/DNS, or am I missing something?

I won't pretend to know what AiMesh requires internally.

> You will eventually want to have ASUSWRT 5.0 (3.0.0.6.*) on all nodes, with or without ASUSWRT-Merlin... imo.

If I wait, should there come a merlin version 3006 for my router or will this not happen?

Read the ASUSWRT-Merlin website. I don't use it.

Did I bet on the wrong equipment? Should I rather have bought some other router?

No, you have good ASUS equipment... it will run next gen ASUSWRT 5.0 that will extend WLANs/VLANs (Guest, IoT, etc. WLANs) to all nodes and has multigig Ethernet for a 2.5Gbps WAN and 2.5Gbps wired backhaul. You just need to install it... beginning with the firmware, Hard Reset, and configured from scratch.

OE

 

[Tech9]

Network configuration is provided via DHCP on a Linux server.
(DHCP is disabled on the primary RT-AX6000)

This may be an issue for AiMesh, especially if you switch to 3006 firmware with separate DHCP servers for the new VLAN functionality. Last time I checked DHCP Enabled on the main router was a requirement for AiMesh configuration.

 

[DianaRea]

I have had issues when the 2.5 GB port is used. Switching to a 1 GB LAN port on the router and the WAN port on the node seemed to "fix" the disconnect issue. Happened regardless of firmware. Do you have a managed switch in between? Is the CAT 6 cable a pre made one or one installed by someone who did not test it?
There is nothing wrong with the Merlin firmware on the router. But it is a good idea to hard reset the node by holding the WPS button while powering on then releasing the WPS button when the power light goes off. Then power cycle.

> I have had issues when the 2.5 GB port is used. Switching to a 1 GB LAN port on the router and the WAN port on the node seemed to "fix" the disconnect issue

Will try this after resetting the router.


> Do you have a managed switch in between?

Nothing in between.
I have tried having a regular unmanaged switch though. No difference.


> Is the CAT 6 cable a pre made one or one installed by someone who did not test it?

It is pre-made, and I have tried replacing it with a brand new one as well.

I have also tested that it works by other means.

 

[Tech9]

DNS is provided by two Linux servers. (primary and secondary DNS)
The primary is doing DNS based adfiltering via pihole.

You may have to redo your configuration. If you have 2x DNS servers and only one is doing filtering some of DNS resolution will go unfiltered. Why this complication with external DHCP, DNS and 3rd party firmware?