Deco M4 keeps dropping ethernet connection to modem and goes Red

Deco M4 keeps dropping ethernet connection to modem and goes Red

Deco M4 keeps dropping ethernet connection to modem and goes Red
Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-18 05:07:25
Tags: #ethernet
Model: Deco M4  
Hardware Version:
Firmware Version: 1.6.5 Build 20241231 Rel. 41802

It has been just 3 days since I purchased a Deco M4 and have had issues since the very first day.  I have one main Deco and one satellite Deco all on the same floor.  The main Deco is connected with the provided ethernet cable to my ISP provided modem/router. I followed all the steps per the app and got it to work on both units.  But only for a while,  about an hour or so after everything is setup,  the main Deco loses its Ethernet connection to the router and the light on the main Deco is solid Red and on the satellite Deco is flashing Red.  So I disconnected both Decos from the power and connected again and after the initial yellow light, it goes back to solid Red and flashing Red.   Then I did a Reset on the main Deco and performed the whole installation setup again.  Yet again , it worked , but after about an hour, the exact same thing again where it loses its ethernet connection to the router (the ethernet light on the router goes off).  Now, the obvious thought would be that there is something wrong with the ethernet port on the router, but there is not.  As soon as the Deco disconnected,  I unplugged the ethernet cable from the main Deco and plugged it into my laptop and the light comes back on and my laptop is able to connect to internet via the ethernet connection.  

I have tried using both ethernet ports on the Deco and still have the same problem.  I have tried using a different ethernet cable and still have the same problem.  After a hard reset, deleting the Deco network and installing again appears to make it work for a while but then it loses the connection again.  I also upgraded the firmware on the Deco using the app and the new firmware version claimed to address some "stability issues" and "fix some bugs" . However, even after upgrading the firmware, I still have the issue where it works fine for a while , then drops its ethernet connection to the router.  

It seems many others have had issues with connection constantly dropping but they seem to be having that issue with the WIFI network.  For my case, the WIFI network was fine as long as the ethernet connection is there.   

Has anyone experienced this and if so how to fix it ?

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8 Reply
Re:Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-18 11:42:04 - last edited 2025-05-18 11:42:53

  @SpaceMonkey 

 

Try this: when Deco mesh is up and running, change it to AP mode and see if it makes Deco mesh stable: Switching a Deco to Access Point (AP) Mode

 

In AP mode Main Deco should be treated by ISP Router just like any other wired to router device, such as desktop PC with Ethernet card. 

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Re:Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-19 13:51:45

@SpaceMonkey Replace the cable that connects the main Deco to ISP modem

Just a M4 (2-pack) user who regrets buying it
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Re:Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-20 08:14:26 - last edited 2025-05-20 10:40:47

  @Alexandre. 

Thank you for the response. I tried your suggestion , made main Deco into Access Point  ,  rebooted before and after and the problem still persists.  Only difference was that the connection lasted longer (about 2-3 hours) than before (about 1 hour).   The major annoyance is that after the connection is lost , I cannot just unplug the ethernet cable and replug again to make it work. Both Decos go Red and need to be reset and the whole thing setup again to make it work.

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#4
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Re:Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-20 08:16:35
Already tried, no difference. Cable is fine , ethernet port on router is fine.
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Re:Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-21 03:16:19

  @SpaceMonkey 

Hi, there is a new version 1.7.0 for Deco M4, maybe you can install this version to see whether it helps:

Deco M4_V1/V2_1.7.0 Official Ready for Test!

 

If, however, the same issue is repeated, before resetting the Deco or making any other modifications, please help me save the web UI system log first:

Deco web interface login

(You can send the log to support.forum@tp-link.com. Please add the forum ID#817226)

 

By the way, may I know your internet service provider? What is the model number of the ISP-provided modem/router?

Wait for your reply.

Best regards.

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Re:Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-21 15:13:05

  @David-TP 

 

Thank you for your response.  When I check my firmware in the Deco app or in the web UI , it says "Your software is upto date".  I understand 1.7.0 is a test version, but I will try it out. 

I just wanted to respond to your question regarding my ISP . ISP is Railwire Broadband and the model name of my ISP modem/router is N2801RW.  It is labelled as a "GEPON ONU 1GE+WIFI"  . Today I am experimenting with just having the one Deco connected and wanted to check if it works without connecting 2nd Deco. I have to give it more time to see if it disconnects. I downloaded the system log anyway since if the issue happens again,  the Deco will be Red and offline and I will not be able to get into the Web UI to be able to download the logs. I will have no option but to reboot/reset.  Please advise how I could get the system logs from the web interface if the Deco network disconnects and is not online due to this issue. 

Thanks. 

 

I am also unable to attach a log file to this message. It says "Failed to upload".  But there are some error messages in the log which may or may not be relevant. 

 

 

 

Wed May 21 18:46:56 2025 user.notice IMPROXY: INFO[imp_verify_multicast_addr@245]: Group address 224.0.0.252 is Local Network Control Block
Wed May 21 18:46:56 2025 user.err IMPROXY: ERROR[imp_group_print@409]: 
interface br-lan:192.168.68.1

Wed May 21 18:46:56 2025 user.err IMPROXY: ERROR[imp_group_print@414]: group 239.255.255.250 exclude mode
Wed May 21 18:46:56 2025 user.err IMPROXY: ERROR[imp_group_print@416]:     group time 260
Wed May 21 18:46:56 2025 user.err IMPROXY: ERROR[imp_group_print@417]:     version: 3
Wed May 21 18:46:58 2025 user.notice IMPROXY: INFO[imp_verify_multicast_addr@245]: Group address 224.0.0.251 is Local Network Control Block

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Re:Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-22 02:13:13

  @David-TP 

 

The issue happened again even though only there was one Deco in the network (2nd Deco was not turned on) .  The Deco light is now solid Red and I believe that it is just going offline after some time due to some defect and may not necessarily have anything to do with ethernet or ISP router.  I downloaded the system logs and have sent it in an email to support.forum@tp-link.com and mentioned this forum id. 

Hopefully it will provide some clue on how to resolve the issue. I appreciate your assistance.

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Re:Deco M4 keeps dropping ethernet connection to modem and goes Red
2025-05-22 09:37:29

  @SpaceMonkey 

Hi, thank you very much for the feedback.

As the laptop works well when it is connected directly to the ISP ONU, have you tried cloning the MAC address of the laptop on Deco to see whether it helps?

How to Configure MAC Clone on Deco if Deco fails to connect to the internet

 

I'll also forward the logs to the engineer to see if he has any other suggestions.

Thanks a lot and best regards.

 

 

 

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