Using a Netgear DM200 with Plusnet FTTC VDSL service

[#1]

I am trying use a Netgear DM200 modem with a Netgear R6350 (router only) on a Plusnet FTTC VDSL connection. I can get the DM200 working in modem+router mode both with a PC directly attached to the modem and with a PC attached via the R6350. However when I switch the modem to modem only mode I can get no internet in either arrangement.

To diagnose the problem I connected the PC directly to the DM200 with a wired connection. I set the PC to fixed IP of 192.168.5.2 with gateway and DNS of 192.168.5.1. This is necessary as when in modem only mode there is no DHCP. I started with the DM200 in modem+router mode. I can then connect to the DM200 browser interface and see that internet shows as OK. It has an external IP address and the status screen shows as connected. The DSL light on the modem shows solid green. I can get internet on the PC. i.e. everything works as expected.

I then change the modem to modem only mode. I can still access the modem browser interface. This still shows internet as OK (green tick) and the modem DSL light is still solid green. However there is no internet on the PC and the modem interface shows 0.0.0.0 for the external IP address and the connection status screen shows as disconnected. If I click the connect button nothing happens. It seems the modem drops the connection when you switch to modem only mode. Rebooting the modem whilst in this mode does not help.

I attach screenshots of the modem screens in both modes.

It seems to me that I need to operate in modem only mode as otherwise you have double NAT and problems with port forwarding.

I am about to give up and return the modem. The supplied Plusnet Hub 1 just about does the job. If anyone has any suggestions though I will have another try. I would be interested to know if anyone has succeeded in getting the DM200 to work in modem only mode with Plusnet VDSL (or any other VDSL service).

[#2]

When you have the DM200 in modem only mode, something else must establish the PPPoE session and thus obtain the external IP. In your case this will be the R6350 . You need to configure the R6350 for PPPoE with your plusnet credentials and then connect it's WAN interface to the DM200.

[#3]

Its the router settings that you need to be looking at, with the nodem in modem only mode.

[#4]

Ok the light dawns. I had naively assumed that, since the modem handles the VDSL input, that would be where you set all the connection parameters. I would never have guessed that you need to do it in the router - which has no modem in it. Bizarre - but there are obviously technical reasons why it works that way. The connection is on a remote site. I will try it out next time I am there. Thanks.