@phillip_mcmahon 

Really? You are telling me off this thread because I am confusing you? pfff.

Alright, I am sorry I hijicked you post, mate. Hopefully you aren't traumatized.

@RodrigoBG8 

Definitely not traumatised. What part of what I wrote in a polite manner gave you that impression.

I pointed out that THE thread (not MY thread) is about issues with the Deco M9 model and the dumb smart DHCP feature while in Access Point mode. You posting specifically on this thread about similar troubles but with a different model in a different operating mode, along with best guess instructions on how to fix the M9 issue isn't making best use of your time, or ours, and seems not the most efficient use of a forum.

I also thanked you for looking and suggested you post a specific item for your issue/hardware combination (hint: not in the Deco forum as you don't appear to have one) so as not to confuse THE THREAD (i.e. change its purpose and waste people's time, not about if confusing me personally. I am pretty savvy when it comes to using forums for their intended purpose).

But of course, if you want to act like a petulant child because someone gave you advice and pointed out the error of your ways. Feel free.

walz wrote

@DLMax I can confirm this is not just an issue with the Deco products, but also exists in the Archer C6 in AP mode. Don't mean to hijack the thread but just wanted to highlight that it's a firmware issue with TP-LINK products across the board. My main network is in 192.168.1.x, but if my main router is not available, the Archer C6 starts assigning IPs in the 192.168.0.x range, and all of the devices connected to it are not able to access WAN.

Oh wow, even standalone consumer units in AP mode as well !

This is beyond crazy.

Thankfully, the EAP line does NOT do this stupid crap. I've switched to using those when I can.

I cannot believe that this Smart DHCP rubbish is actually considered a "feature". It's a design bug and the team/person who came up with it belongs with the team who invented Windows Vista.

Does anyone know if this "feature" is on the Deco X20 and X60 models? Hopefully not.

Still no news? Should we go for other brands?
Maybe we can hope an answer somewhere else?

@thepopol777 

So, this may help those running OpenWRT and encountering issues with their Access Points starting up "Smart DHCP" servers, which my M9plus do in AP mode.

In the web interface, OpenWRT -> Network -> Interfaces -> LAN -> Edit (on right) -> DHCP Server -> Advanced Settings (tab)

There is an option for:

"Force DHCP on this network even if another server is detected."

Also, while you can't set the static IP of the TP-Link APs (I have 6), it might be worth setting the lease time to "infinite" without the quotes in the address reservation section of the DHCP config.  I don't know if it is when the APs need to renew their addresses or if it is just when a client connects that they enable their Smart DHCP, but anyway, "infinite" is an option in OpenWRT (which appears to be more like 90 days, but nonetheless a fairly long time).

The TP-Link APs do seem to fall in line when the OpenWRT router has its DHCP server on...and this should make the OpenWRT router go ahead and start its own, so I'm hopeful it suffices.

Following up on the OpenWRT solution, rebooting seems to be fine with this, and the primary Deco was the first client to associate.

Still...the Decos seem to randomly hand out addresses.  I have bandwidth monitoring, and I'll get random IPs jump up and do DNS requests.  I think this has caused some havoc with my WEMO lights associating with another address that isn't on my network and then appearing offline.

So, it still is a major problem that when the Deco is in AP mode that they would hand out an address....EVER.  They shouldn't...it just messes things up.

"So, it still is a major problem that when the Deco is in AP mode that they would hand out an address....EVER. They shouldn't...it just messes things up."

@Sol Totally agreed, and thanks for the useful tip, as any mitigation, even if partial, is helpful in dealing with the CF caused by this TP-Link 'feature'.

@ZeroBufferBloat 

I've rebooted 4-5 times now, even powered down for a while and powered back up.  For OpenWRT routers, that does seem to be successful.

Another thing I've noticed, the Deco denoted as Main obtains a DHCP address within a minute of the router coming up.  It is typically among the first 3-4 devices (we have 130+) obtaining an IP address.  The other 5 M9 Plus Decos eventually do get around to requesting an IP address, but they aren't as aggressive about it.  I don't know that this is here nor there other than to say the Main Deco is very actively looking for a DHCP server to come up...and when it is, it requests an IP address almost immediately (presumably at that point it shuts its down...but like I say, it still hands out a random one here nor there...probably 3-5 per day).

Setting your lease time to a longer time would probably reduce the number of errant DHCP IPs.  I have my lease time on my OpenWRT router set as 1h, and over the past 24 hours, there are 6 IPs that have been handed out that are not on my subnet.  There really is no excuse for that behavior.