@Kevin_Z Thanks, I already know the difference and I want to setup Deco in Router mode.

@rbsub 

Hi, 

After lot of reading on internet, I have found below setup to avoid the double nat issue.
Here is my setup,
Vodafone connect router having internal IP 192.168.a.b connected to the internet and have wifi turned off and dhcp turned off. DMZ set to forward all traffic to internal IP of DECO 192.168.a.c
Decos internal LAN ip is set to 192.168.x.y and gateway as 192.168.x.y where all the other devices in household connect. 

With above I do get internet, but the netowork is very slow, the pages take long time to open. my plex media server which is on same network keeps losing connection.

Can anyone please suggest on the config should be done to get best results? 

Thanks

@rbsub 

Any news? 

I also have Deco installed on a HS8247W Vodafone ONT. 

Also have a TV box that loses connection all the time and also Wi-Fi devices with same problem. 

Any configuration that helps? 

Also deactivated Wi-Fi on Vodafone router. 

Thanks 

@Enfermeyro 

I have started using Deco in Ap mode. 

Still have issues with connection dropping on my plex server when watching from TV. No issues when watching from phone. 

Seems like I paid too much for most of the features which are not usable.