Conflicting DHCP when Deco in AP mode ?
Today I ran into an issue which made me almost cringe.. as I hadn't expect this to happen, considering I've been working in the IT networking business for over 30 years..
I had recently purchased a Deco M5 mesh set with 3 nodes and setup as AP access points, because I alread have a decent router from my ISP (Zyxel EMG2926). This has been working fine for the last 6-8 weeks and nothing to complain about.
Last night, for some strange reason my router rebooted and I lost Internet connexion from everywhere, including my wired PC's which I use every day to work from home.. So getting back internet was critical to me and I tried the quick obvious options like rebooting the router and also reseting to factory the router, then reloading the configuration I had on backup.. To no avail, I wasn't able to get an functional internet, still the router diagnostic was able to ping any IP address outside my network.. Since I needed to work and support clients, I disconnected the Zyxel router and put back the Mercku M2 Hive base I had prior to the ISP router and after 5 minutes, was back into business.. (The Mercku is also a Mesh Wi-Fi system with 4 Bee nodes, albeit it wasn't working to my entire satisfaction, thus the purchase of the Deco M5).
Having spend the morning with work, I had hope the issue with the router might have been on the ISP side, so tried to set it back in action. Result was identical and nothing was really working.. Put the Mercku M2 back for the PM as I had a support call and did need internet ASAP.
At the end of the PM I got back to my router and it was so weird that I even tried to reset the Zyxel for the n-th time and start from scratch.. What puzzled me was that it was working if I forced my computer into fixed IP address, and even with DHCP Mac address reservation, the router wouldn't route my requests properly to the internet.. Looking at the IP addresses in the config made me think that router was totaly corrupt and crazy.. The router's IP is 192.168.127.1, but returns 192.168.127.102 as gateway and .254 for the DNS server, which is even crazier.. This is when I started to scan my network for rogue devices with my Android smartphone, but couldn't find anything suspicious. I've a lot of IoT devices and aside of the 3 Deco M5 AP's, there was nothing un-usual. However, the .102 IP address made me tick and look closer at the Mac Address, to finally discover that the main Deco M5 unit (the one connected by Cat5 cable to the switch) was the culprit.
For some obscure reasons my Zyxel router was thinking that the Deco M5 AP unit was the master DHCP on the network, despite TP-Link saying in their documentation that it is not the case when in AP mode.. As a proof, my Mercku M2 router had no issues at all with that and was perfectly handing over IP addresses to all devices..
Has anyone run into such a situation with another HW router ? getting conflicting DHCP server mode while the Deco M5 is in AP mode ?
I fixed my problem my disconnecting the Cat 5 cable temporarly from the switch, rebooted the Zyxel router and voilà.. after it was back as 'master' DHCP, I plugged the Deco M5 back and all was working as before.. But I'm really curious about that strange behavior.
Any comments are welcome on this.
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Hi, my previous contacts with support were not very useful....
But there is not much to say : i just disable it, and the day after it is enabled in the app.
nothing changed on the network.
last firmware on X20. last version of the app.
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Nice to see you again.
This feature has been added on most of the models, like Deco M5/M9 Plus, Deco M4 V1/V2, Deco X60 V2 as well as other modems(Deco X20 V2/W3600/X90/XE75) with firmware above 1.1.0. But some of them has not added it.
"Smart DHCP" is not a useless feature and there are other brands that use this feature in different forms as well. Like we mentioned before(Here), it is not activated for no reason.
We appreciate that you could share your review with us and also want to explain our concerns in a different aspect.
Thank you very much.
Best regards.
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To date, no one has explained how firing up a DHCP server (in a non-deterministic way) that dishes out IP addresses from a different and non-configurable scope does anything other than break a network. Neither has anyone explained why this wasn't an option available from the start with the ability to fully disable when the devices should have been fully transparent from a network services perspective. What if someone does not run a DHCP service, and assigns IP addresses statically yet wanted to use Deco devices in AP mode...
I see that many people are experiencing the setting switching from disabled to enabled without them doing anything. Clearly issues still to solve.
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@David-TP what's the point of sending this info to you guys. It a really easy feature to implement, especially for a big brand like TP-Link.
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@Templier unfortunately it's not for V3...
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This is crazy.
3.5 year old issue and they still can't even release code for the various hardware versions people have bought. The entire deco product line is possibly the worst I have seen for quite some time.
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Good afternoon, is there a solution for this problem in the Deco X20? I have the problem that the SMART DHCP is activated from time to time. The firmware is updated to the latest version.
Thank you.
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I was contacted by support. Provided logs. Since no news...
You should open one too, send logs, might help finding the issue, cause they were unable to reproduce the issue in their lab they said.
I don't believe it will go very far... but was quite easy to open the issue.
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