@Marco82 

Hi,

Be careful when configuring two DHCP servers within the same network. The IP address pools must not overlap with each other, like you've already mentioned, and also make sure the default gateway is the local IP address of the networking device that provides the Internet connection, which in your case is the VX220-G2v.

At the time when the problems with the router's 2.4 GHz and 5 GHz wireless connections occur, check the IP addresses (incl. Gateway and DNS) that the client devices have assigned to them are correct.

  @woozle 

Thanks for your reply.

It' what I did. I made sure that IP pools are not overlapping and that the default gateway of the extender is 192.168.1.1 which is the default one of the router.

What else am I missing? May be a faulty unit?

I can navigate only through the regenerated WiFi network. My other original 5Ghz gives no access to internet... :(

Regards,

Marco

  @Marco82 

Even if the WA850RE was faulty it should not affect the 5 GHz Wi-Fi of the VX220-G2v.

If you haven't done so already, could you please connect any client device to the 5 GHz band of the router and when it doesn't give access to the Internet check all the addresses assigned by the DHCP on the client device itself?
On a Windows 10/11 computer all the information can be found under properties. On Android phones it depends on the particular phone how much information is shown within the settings menu, but if you install an app like AIDA64 you can get all the information.
Verify that the IP address and subnet netmask assigned to the device reflect the correct network setup and that the Default Gateway is the LAN address of the VX220-G2v and the DNS is also either the LAN address of the VX220-G2v or the address of an actual DNS server.

  @woozle 

Thanks again for your reply.

Here what I have when connected to my 5Ghz network.

Cannot reach 192.168.1.1, or anything...

If I unplug the WA850RE, everything comes back operative...

Regards,

Marco

  @Marco82 

Ok, I see. When connected to the 5 GHz network your Windows PC is not retrieving any IPv4 addresses at all.

The wireless extender must somehow interfere with the DHCP broadcast or the DHCP server, although I don't know how this is possible.

Is your TL-WA850RE already running the latest firmware version 1.0.12 ?

  @woozle 

Yes, that firmware, build 221109 rel.31477n.

I also have a Synology NAS connected via LAN to my router. When I have no connection, I can reach it via mobile phone, but I cannot tell about performances..

Regards,

  @David-TP 

Hello David, thanks.

It usually happens once a day. I have to unplug it or connect to the extendend network or go to sleep, because it's late :D 

Thanks,

At the moment I noticed that my phone is working properly in the 5Ghz wifi network... Days ago it didn't work either. So, I must think of something temporary in specific device network status...

  @Marco82 I was about to pull out my hair in frustration! I have changed several things at once on my wi-fi network, and I have been battling for over 2 weeks with network problems.

I am having the exact same problems as you described. Devices loosing internet access or getting very slow or not getting assigned ip addresses from my DHCP server.

Even when I assign a manual IPv4 address on my Windows 10 and 11 PCs, ipconfig states it is using a 169.*.*.* address because my manual 192.168.*.* address is Duplicate and already used on the network! Although, trying to ping the address from another device yields no results.

When I set the PC network adapter to Automatic obtain from DHCP and run the IPCONFIG /renew command, it will also state that it have received an IP address already in use on the network and that it will disable the interface.

Sometimes, things would just randomly start working again for a while, and the same problems start.

On my network, I have a total of 3 TP-LINK range extenders, namely a WA850RE, a WA855RE and a RE200.

When I did the major changes on my Wi-fi network, it was the same time I installed the WA850RE unit.

Just yesterday, I realized whenever my network problems popup, I must unplug or reboot the WA850RE unit and everything would start working again. However, after some several hours, the problems would be back and I rinse and repeat.

All latest firmware are installed on the WA850RE, but the problem remains. Think I am going to return the unit for a refund, although I threw away it's box, but I am just going to "accidentally" return in in the RE200 box I bought a week after the WA850RE... 🤣

It seems that after a while, the WA850RE unit starts to interfere with the DHCP packets on the network. I have disabled the DHCP server on all 3 devices away from the default "auto" setting, but this changes nothing.

I was also running 2 DHCP servers from the same pool with non overlapping ranges like I was doing for the past 2 years with no problems before I installed the extender. I disabled the 1 and it seems to very slightly make things better, but the problems are still there.

The Hardware and firmware details are:

Hardware Version: TL-WA850RE 7.0

Firmware Version: 1.0.12 Build 221109 Rel.31477n (6985)