@Alexandre. Hi Alexandre,

as a relative newbe I havent tried this so will try and see if it makes any difference.

My ISP's Digital Voice service is integrated with the broadband service, their router has to connect using PPoE so will reconnect this to the service and then connect the main Deco to that with the Deco configured to use dynamic ip ............ will need to look into this to understand how this will work. The DHCP server in the ISP router/server will be disabled .......... I guess the bit i dont understand yet is how the deco gets its ip address .......but thats a bit of reading for me  to do :-) and of course I assume using the dynamic ip setting I can still use the deco DHCP server.

  @Dave_Wood Dave, sorry to be that guy that says "I need more I formation", but what services does the hub from your ISP provide? I have always used the modem from my internet provider as simply a connection to the outside world, and out my own (typically wireless) router behind it. What are you trying to accomplish and what are you not able to do?

  @HHaas 

Hi just to let you know we seem to be up and running :-)   I guess double NAT is a possible problem but no gamers here and although two DHCP servers running (different address ranges) I do not seem to have any problems as all the attached devices on the Wifi network and local Ethernet network appear to be picking up IP addresses from the DECO X60. I do not know enough about subnetworks and DHCP server to know whether this configuration will become a problem in the future. I know some of the smart speaker configurations require all the speakers to be on the same network ( I assume same sub network). But it is working at present so we see how we get on.

tks for help.

Set up as below :