Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect

Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-01-23 02:55:41
Hardware Version: V1
Firmware Version: M9 Plus: 1.3.0 Build 20190821 Rel. 54023 M5: 1.4.0 Build 20191223 Rel. 38921

I appologize this post is a bit long, but here's the executive summary of the issue I'm having: 

My network of 5 Deco units (2 M9 Plus & 3 M5's) keeps dropping devices off the network and those devices try to reconnect but get "Failed to obtain IP Address" errors and never reconnect.  The only solution I've found is to completly power down my entire house via the circuit breaker and slowly enable power around the house to reconnect a few devices at a time.  Then it's only a matter of days before devices seem to start dropping off again!

Feel free to read all the details below if you're interested or can help!  Thanks!

 

More Detailed Story:

I had 2 Deco M9 Plus units in my house working well for the past year.  I have been adding more and more wifi devices over the last year, and now there are typically about 60 devices connected at any time.  About half of those connected devices are TP Link Kasa smart switches/plugs.  To handle the increased capacity and get better coverage at the extremities of my house, I decided to add a few more Deco units to my setup.  About a two months ago, I purchased 3 Deco M5 units and added them to my network. 

As I built out the network connecting each new Deco unit or new device, things seem to work just fine.  However, in the last few weeks, I now have severe issues with devices getting disconnected and not being able to connect back to the network.  The devices all attempt to connect to the network but get “Failed to obtain IP address” errors.  For example, at some time between 8am and 10am this morning about 25 of the 60 devices on my network were somehow disconnected and have not been able to reconnect for the last few hours. 

There seems to be no pattern or reason as to when or why these devices disconnect (or fail to reconnect).  This seems to happen every couple of days now and has probably happened 5-6 times in the last two weeks.  And it's a different group of devices every time.

I’ve tried various things like unplugging/rebooting/reconnecting the devices, but that doesn’t seem to ever work.  I’ve tried unplugging/rebooting the deco units; that doesn’t seem to work either.

Once the network gets in this state, the only solution I’ve been able to come up with is to use the circuit breaker in my house to shut off the power to most of the house and then incrementally flip the circuits back on to have a few devices connect at a time (starting with the circuits my Deco units are on).  

I saw the recent 1.4.0 firmware update for the M5 units, so I applied that update hoping it would help the issue.  No luck.  I haven’t tried the 1.4.2 firmware yet (and the release notes didn’t make it seem relevant to my issue). 

I got desperate the other day and decided to do a factory reset on all the Deco units.  I reset them all, made minimal adjustments to the default settings, and reconnected my 60+ different devices.  A day and a half later, I’m experiencing the same problems.  Devices started getting disconnected (and won’t obtain IP addresses and reconnect) again.

Here’s my setup:

  • Internet à 1st M9 unit which connects to 3 other decos:
    • 1st M5 unit
    • 2nd M5 unit
    • 2nd M9 unit which connects to:
      • 3rd M5 unit 
  • Typical load of network devices:
    • ~20 TP Link brand smart switches (HS200 & HS210 models)
    • ~10 TP Link brand smart plugs (various models)
    • ~10 cell phones/tablets
    • 4-6 laptops
    • Various other smart home devices (thermostats, cameras, garage door, etc)
    • Various other entertainment (smart TV’s, gaming consoles, etc)
  • Deco firmware versions
    • M9: 1.3.0
    • M5: 1.4.0
  • I have made very minimal changes from the factory default settings.  Here’s what I have done:
    • I do have address reservations setup for all of the smart switches/plugs plus a few other devices
    • I am using the parental controls for a handful of my kids’ devices
    • I turned on the antivirus options (now turned off, but doesn’t seem to matter)

 

When I try to look through the Deco’s logs, I see a lot of repeated messages that look like this (but with different IP addresses and static lease values):

Fri Jan 10 20:32:51 2020 daemon.err udhcpd[8648]: Sending OFFER of 192.168.68.202

Fri Jan 10 20:32:52 2020 daemon.err udhcpd[8648]: Found static lease: d344a8c0
 

My only guess to what’s happening is that the deco units are getting overloaded with connection requests and failing to connect any of the devices.  This seems to align with my only solution (using the circuit breaker to connect a handful of devices at a time).  But clearly this is not a viable long-term solution when half the network gets disconnected every other day. 

If anyone has any ideas on how to fix or debug the issue, I'd love to hear them.  Thanks in advance!  

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9 Replies
Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-01-23 19:06:20

@JimGT 

 

 

Simple answer is the 1.4.0 is likely the issue.  We recommend upgrading your Decos to 1.4.2 as soon as you are able to and the issues should for the most part disappear.  If not we can dive more into it but the new firmware should fix those issues 

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Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-01-31 01:57:02

@Carl 

 

I updated the firmware on the M5 units to 1.4.2.  However, I still am experiencing the same issue.

 

Just a few hours after the firmware upgrade, approximately 40% of the devices on my network dropped their connection and are getting unable to obtain IP address errors.  

 

 

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Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-01-31 14:33:31

@Carl 

 

My network started dropping devices (and not being able to reconnect them) for the second time within 24 hours of applying the 1.4.2 firmware to the M5 units.  

 

Rebooting the main deco allows 5-10 devices to connect, but the other 50+ devices are left in a "failed to obtain IP address" state.  Multiple attempts to reboot the decos have the same effect - it's just a different 5-10 devices that connect each time.  

 

It's like the network is getting overloaded and only a few devices can get connected before the overload prevents anything else from joining.

 

My only solution is still to use the circuit breaker in my house to turn everything off and then slowly turn everything on room by room.  This is not a viable solution when this issue is happening multiple times a week (or even a day)!

 

Please help!

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Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-01-31 15:31:03

@JimGT 

 

 

Jim sorry we had an issue yesterday and i was not able to access the community.  I will forward this to our test engineers and see if they can shed any light on this.  As far as i am aware 1.4.2 is a stable firmware so I will need to engage with them.  Once i have word I will let you know. 

 

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Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-02-04 17:26:17

@JimGT 

 

Hi Jim.  We need to provide the engineers a few things

 

1.  The Email address used to setup the Deco Account.  Is it the same as the email address used to create your community account?

2.  The Logs from the Deco. 

 

They can be sent to ussupportteam@tp-link.com.  Please include a link to this thread so we know who the belong to. 

 

 

thank you 

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Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-02-07 17:13:27

@Carl 

 

1. Yes, same email address.

2. As for the logs, do you need them from a time when the issue was occurring?  The latest log file I tried to download just had activity for the last couple of hours.  Fortunately, I haven't had this issue since last Sunday.  Is there a way to access older log files?

 

Thanks, 

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Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-10-09 17:29:46

 

JimGT wrote

@Carl 

 

1. Yes, same email address.

2. As for the logs, do you need them from a time when the issue was occurring?  The latest log file I tried to download just had activity for the last couple of hours.  Fortunately, I haven't had this issue since last Sunday.  Is there a way to access older log files?

 

Thanks, 

I have the same issue did you find the solution?@JimGT 

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Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-10-12 13:19:10

@Liza_M_Aguilar 

 

I still have the same issue.  After many hours of debugging and many hours of TP-Link support connected to my system, the only progress I was able to make was to confirm that the router is getting overloaded with DHCP requests. 

 

I have done extensive testing to see if one of the M9 or M5 units is to blame or if a specific device on the network is causing the issue.  For example, running the network with only specific units on or off.  Long story short, it does not appear device specific.  The first device(s) to lose connections and start bombarding the network with DHCP requests are always different - no discernable patterns.

 

The partial work around for this is to change the IP configuration on each device to have a static IP (no DHCP).  I made a spreadsheet to track all the IP's I assigned to devices on my network so I don't assign anything the same IP.  I have updated all the devices I can (computers, phones, tv's, etc) to have static IP's. 

 

The issues with this partial work around are:

  1. Certain devices (like TP-Link brand smart switches) only do DHCP.  The devices that only do DHCP will eventually get stuck trying to reconnect and remain offline.  After resetting the entire network, sometimes they will stay connected for weeks - sometimes just a few days before problems occur. 
  2. Guest device wifi - once my network gets into a bad state, the only way to connect anything is with a static IP assigned.  Obviously, trying to tell a guest in your house how to setup a static IP (and pick one that isn't already taken) is less than desirable and essentially turns into something that only I know how to do.

 

I keep hoping every new firmware update will fix this, but it never does.  

 

At this point, I'm pretty annoyed with TP-Link and will never buy another one of their products.  It's ridiculous that the routers are getting overloaded by DHCP requests and their logs are so pitifully small that unless you find the issue within the first few minutes of it occurring, you lose the history of what happened.  After spending hours connected to their support line and talking to engineers, they had no answers.  They captured a lot of data and said they'd get back to me but never did even after I tried contacting them again.  Unfortunately, I've got 40+ of their devices installed around the house, so it's going to be slow to replace it all.  

 

If anyone can recommend a really great mesh wifi system for a large house, please let me know :-)

 

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Re:Devices lose WiFi connection and then "fail to obtain IP address" when trying to reconnect
2020-11-28 20:07:09

Just an update on the situation here... the issue described above definitely appears to be caused by the Deco units' poor DHCP server implementation.  

 

A few weeks ago, I switched all of my Decos into Access Point mode and turned on the DHCP server on my ISP provided modem/router.  I've had zero devices lose their network connection since this I made the switch.  

 

It's quite disappointing that the Deco system can't even match what my 5+ year old ISP modem can - namely, successfully acting as a DHCP server for the ~70 wifi connected devices in my house.  

 

It's also quite disappointing that I have to disable all the other features of the Deco system (e.g. Parental Controls) just to turn off DHCP on the Decos.  I feel like a standalone option to disable DHCP has been a basic feature of every networking device I've used in the last 20 years.  

 

I really like the vision for what TP-Link was trying to accomplish with the Deco product line, but unfortunately there seem to be many limitations lurking just beneath the surface that render these devices as very poor networking equipment.  I'll limp along with my current setup for a little longer, but I suspect these Deco units won't last much longer in my house.

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