Is there a logout button on the web interface? Did you log out locally?

Network name should be the same, so that they can communicate with each other?

Hi Nick, Multi-NAT fuction? If you read this artical, you will know TD-8840T v4 has no such a feature. http://www.tp-link.com/en/article/?faqid=383

Upgrade the latest firmware, reset and reconfigure it. http://uk.tp-link.com/support/download/?model=TD-W8980&version=V1#tbl_j If the problem continues, submit a ticket here....

You should go back and login configuration page of W8951ND before you ask so many questions... 1. Change IP address to be the same subnet as the root router. I didn't say change IP address to be the...

When the 3G signal drops or becomes 2G, if the modem is plugged into your PC to access internet, is it working properly all the time? Give a try.