Neither C2 nor C20i can ping from WAN... They are designed to work in this way and they won't respond to ICMP pings...

The main router works fine, right? Did you test the connection directly to W8980? As to WA750RE, firmware is up to date? How about status of all lights when it stops working? Can you see the range...

With parental control, if you don't add a keyword in whitelist, you should be able to block all websites. Give a try. Access control of VR900 has no time restriction...

I didn't get what you are trying to fulfill... The strange thing is that on the MAC Filtering section a device will show up as blacklisted but also appear simultaneously in the device on line...

Firmware is up to date? Can you test the upload speed in a different way and make a comparison with speedtest result? Post screenshots of your test results.

What is the model number pls? WPA4220KIT? Yur tried the password of your main router. How about the 8-digit password printed on the back of powerline extender? If neither work, try to find it out on...