@pandeya1979 Hi, please refer to this guide for troubleshooting: TP-Link Range Extender Stops Working If there is any further issue, please let us know the LED status of the extender.

@MysticMac Hi, I mean the Ethernet connection between your ISP modem and the main C6 router. Besides, do you notice the Internet LED on the main C6 router goes red when the issue happens? especially...

@Brummerh Please try to change the WiFi channel and channel width to see if it helps, if not, please let us know which WiFi band has the issue, also provide the model no. of your computer and its...

@Ferasalwannous Hi, you mean there is no IP address and DNS on your client device or on the WAN side of the TD-W8961N? Please share with us the whole Status page of the modem router to check the ADSL...

@royketelaar Hi, please check if there is Internet IPv4 address on Advanced->Status->Internet part, if not, I guess you have Internet IPv6 address, please go to Advanced->Network->Internet page,...

@rashid19961 May I have a screenshot of your existing port forwarding settings and also the screenshot of the error message? You mean the same settings was working fine before you updated the current...