@PinkyS Upgrade the router FW to the latest one from here. Can you post these sceenshots: Who is your ISP, do you have a direct cable to C20 or it is connected to an ISP modem/router ? Are you aware...

@hidalgo22 Do you have more than one tp-link device in your network ? Try connect to the router directly via wi-fi (details for SSID/wireless password - sticker on the bottom of the device). Then...

If your device is still under warranty then contact the retailer for help. If he can't help then contact your local support for a resolution.

@GA_Polo OK, so after all the correct public IP address is updated into the no-ip database. Can you move the C6 web management port from the default port 80 to something else (8080 for example) and...

@GA_Polo OK, got it. I didn't know that you have a few router devices behind the ISP router. I assume you already did this to resolve the no-ip.com IP address: Can you make this change and test if...

@RFP "Isn't it strange that I can't "see" the C6 from the C80? It does not appear in the network map nor the DHCP Client List." Probably missing from the C80 network map, because of the WDS mode that...