@Vaclavpe Probably you won't see the extended router as a client of the main one. It's enough to check that on the extended router - " Now you can go to Advanced > Status > Wireless to check the WDS...

@millesm As per your user manual : Try to hard reset the device (Method 1) to see if it will start up normally.

@scoutp1 Is that the router in question ? If it is, then looking into the tech specs you can see that its ethernet ports are only 10/100 Mbps capable. If you want to achieve the advertised speeds of...

@scoutp1 Please, describe your setup/topology and hardware (router model, HW version, FW version, etc.) in more details for the purpose of troubleshooting.

@Vaclavpe Use this guide for configuring WDS. If your main router is Archer C6 then the WDS settings should be made only on the extended router (according to its Web GUI interface - Tenda, Asus,...

@Paranoid3500 Set the wireless security settings like this: then reboot the router to force all your devices to reconnect and test.