Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul

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Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul

This thread has been locked for further replies. You can start a new thread to share your ideas or ask questions.
Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul
Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul
2022-08-09 16:56:23
Model: Deco M9 Plus  
Hardware Version: V2
Firmware Version: 1.5.6 Build 20211018 Rel. 35617

Symptom
I've noticed that under specific circumstances, clients can't connect to the 2.4GHz band on one of my satellites (the one connected by ethernet-backhaul).

 

Topology
I have four Deco M9Plus v2.0 running firmware 1.5.6 Build 20211018 Rel. 35617 in Access Point mode.  Two of the satellites are connected using WiFi and directly connect to the main Deco, one is connected using ethernet-backhaul, so it's a star network.

 

Usually Completely Normal Connectivity on All Disks
If I bring the network up one disk at a time: main disk first, then WiFi-connected satellites, then ethernet-backhaul connected satellite, everything works fine.  Clients can connect on both the 2.4GHz network and the 5GHz network on all disks.

 

If I use "Reboot All" or if there is a Power Failure
When the ethernet-backhaul connected satellite is online at the time of the reboot, then clients will not be able to join the 2.4GHz network on that just that disk.  The same clients can join at any of the other three disks, but receive an "Incorrect Password" response from that disk.  5.0GHz clients can join perfectly well everywhere.

 

On the ethernet-backhaul connected satellite, the 2.4GHz SSID is being broadcast (confirmed using inSSIDer and showing up in the list of available networks for the 2.4GHz-only clients). The same client can be transported to within range of the Wifi-backhaul disks and will connect fine, so it isn't a client problem

 

Theory
It looks like the configuration of the ethernet-backhaul connected satellite containing the passwords - which I assume is downloaded at boot-time from the main Deco - is invalid if it is online at the time the main Deco boots.  It works fine if introduced into the network the other disks have settled down.

 

I've also tried a Deco M5 running firmware 1.6.0-220525 as the satellite and it shows exactly the same behaviour, so I would assert it's a firmware bug in the main Deco and not in the satellite.

 

I haven't tried updating the disks to the 1.6.0-220720 beta.  The inconvenience of having to run around the house to reboot the disks in the right order is less than that of testing beta firmware.

 

Test Environment
The easiest way to reproduce the problem is to configure the guest network to be 2.4GHz only.  You can then easily see a client such as an iPhone being able to join the guest network in the situation where the there ethernet-backhaul connected satellite is brought up in order (last), and gets an "Incorrect Password" response after a "Reboot All".  The same iPhone will always be able to join the network at the main Deco on the guest network.

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#1
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6 Reply
Re:Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul
2022-08-10 07:03:23

  @kevin_marchant 

Thank you very much for your feedback.

Earlier I had seen a similar case: https://community.tp-link.com/en/home/forum/topic/576018

But only the guest network had the issue. Here you mentioned both guest and main network, but in the description, no tests about the main network have been performed. I believe you had the issue only on the guest network as well?

And Did the Ethernet backhaul satellite M9 Plus/M5 used to connect main Deco M9 plus via Ethernet cable directly, not via a network switch?

 

Wait for your reply.

Best regards.

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#2
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Re:Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul
2022-08-10 09:46:35

  @David-TP It affects both main and guest network 2.4GHz clients on the Ethernet-backhaul connected satellite

 

The satellite is connected directly from its RJ45 to the main Deco's port 2 RJ45 by a 15m Cat6 Ethernet cable.

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#3
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Re:Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul
2022-08-11 10:36:59

  @kevin_marchant 

Thanks for the update.

As for the Test Environment
The easiest way to reproduce the problem is to configure the guest network to be 2.4GHz only.  You can then easily see a client such as an iPhone being able to join the guest network in the situation where the there ethernet-backhaul connected satellite is brought up in order (last), and gets an "Incorrect Password" response after a "Reboot All".  The same iPhone will always be able to join the network at the main Deco on the guest network.

 

Could you please help me confirm several details:

1. If the guest network is on 5ghz only, the connection of iPhone to ethernet-backhaul satellite M9/m5 would be fine, right?

2. Were you able to produce this issue most of the time?

3. May I know the model number as well as the IOS version of your iPhone?

 

At the same time, I would like to forward your case to the senior engineers for further assistance.

Please check whether you have got an email from us.

Thank you very much.

Best regards.

 

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Re:Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul
2022-08-11 11:07:56 - last edited 2022-08-11 11:09:25

  @David-TP  Hi David,

 

  • I haven't tested 5GHz only - just 5GHz/2.4GHz and 2.4GHz only.  If the guest network is 2.4GHz/5GHz the iPhone will connect fine to the ethernet-backhaul connected satellite on the 5GHz channel.  I'll see if I can get the opportunity to test 5GHz only.  

 

At the moment I've got the guest network configured as 2.4GHz only, with "Isolate from Main Work" OFF.  I've found issues with band steering and this configuration allows me to ensure 2.4GHz devices, such as the Tapo plugs, connect to a network that is 2.4GHz only i.e. I'm using it as an extension of my main configuration rather than as a true guest network.

 

  • It happens every time I "Reboot All" or after a power failure.  If I bring the disks up in sequence everything works fine everywhere.  It's the kind of problem you like to hear about as it absolutely reproducible, so if your second/third line support people setup a similar configuration I would hope they will see the problem.

 

  • It happens to be an iPhone X running iOS 15.6, and I also tested using my old MacBook Air running MacOS 12.13.6.   So for testing those are suggested devices.  The problem itself affects TP-LINK Tapo plugs (2.4GHz only), a British Gas Hive Leak Sensor (2.4GHz only).  So definitely not a client problem.

 

I'd be interested if your support engineers are able to reproduce the problem in their lab.

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#5
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Re:Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul
2022-08-11 11:41:46

  @kevin_marchant 

Hi, Thanks for the quick reply.

The engineer is testing now and so far I haven't got the update yet.

But I noticed you mentioned that:

At the moment I've got the guest network configured as 2.4GHz only, with "Isolate from Main Work" OFF.  I've found issues with band steering and this configuration allows me to ensure 2.4GHz devices, such as the Tapo plugs, connect to a network that is 2.4GHz only i.e. I'm using it as an extension of my main configuration rather than as a true guest network.

 

If I am right, were you trying to say, with "Isolate from Main Work" OFF, these 2.4ghz-only devices are able to connect to the 2.4ghz guest network of Ethernet-backhaul satellite M9/M5?

Since it was mentioned at the very beginning that both2.4ghz band main and guest network of Ethernet-backhaul satellite M9/M5 had this issue, if that is the case, whether  "Isolate from Main Work" on or off should not make any difference.

But if it does behave differently, I have seen before some users have a customized DNS server in the LAN and it is considered a host device. When 'Isolate from Main Work" is on, the guest devices will no longer be able to access the DNS server, so they could not have internet service either.

 

Please free to tell me if I'm wrong.

 

Thank you very much.

Best regards.

 

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#6
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Re:Can't Access Main Or Guest Network on 2.4GHz Band of Satellite Connected By Ethernet-Backhaul
2022-08-11 12:03:31

  @David-TP Let me try to be clearer.

 

There is the

  • broken configuration created when the disks come up in an uncontrolled manner via "Reboot All" or after a power failure, and the
  • working configuration created when the disks are brought up in an orderly manner.

 

In the broken configuration, no 2.4GHz devices can connect to the ethernet-backhaul connected satellite.

 

In the working configuration, all 2.4GHz devices can connect to the ethernet-backhaul connected satellite.

 

As you suggest and as far as I an tell the "Isolate" setting makes no difference.  I mentioned my configuration so that the engineer can accurately recreate my environment if the problem doesn't display itself initially.

 

As both the main network and guest network are "joined" i.e. not isolated, they both share the same DHCP / DNS configuration, which is very simple.  I'm using my Asus router as the DNS and DHCP servers. 

 

The key thing here is that if I bring up the disks in an orderly way (all disks powered off; turn on main Deco and wait for green light; turn on wifi connected satellites and let settle; turn on ethernet-backhaul connected satellite; it all works perfectly for weeks and weeks.  The inconvenience of this edge-condition is quite minor - it's not like I can't use the network most of the time.  

 

I must say that I'm really pleased with the disks and the facilities provided.

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