ADSL/VDSL modem router in bridge mode in conjunction with wireless router/Deco avoiding Double NAT

In the following diagram is the typical network topology:

Before you start, I would suggest to backup the TD-W9960 and C80 configuration just in case something goes wrong.

You will need these credentials for configuring PPPoE session in C80 later:

 

 

Delete the old Internet connection in TD-W9960 (PPPoE):

 

 

Add new Internet connection of type Bridge (click Save at the end):

 

 

Note: Make sure the modem LAN DHCP server is disabled - some modems may need this setting changed.

 

Settings in C80:

 

If you ISP uses a particular VLAN for the Internet, IPTV or VOIP you can set these here (captured from TD-W9960 in the first step):

 

 

Configuring PPPoE session in C80 (captured from TD-W9960 in the first step):

 

 

After configuring the PPPoE in C80 click CONNECT (if available) and you should be able to establish the PPPoE session from C80.

You'll have an internet connection with a Single NAT in C80.

Similarly you can use other TP-Link ADSL/VDSL modem instead TD-W9960.

Also you can use Deco system (in router mode) or any other wireless router instead C80 depending on what hardware you use.