Nighthawk M2 (MR2100) preventing Synology NAS from connecting?
I recently moved to the country. In the city we had cable broadband, but at our new house there is no hardwired internet, so we need to use mobile broadband, and got a Netgear Nighthawk M2 router/wifi unit (model MR2100) from Telstra. I have a Synology DS411J NAS which all our iMac and Mac laptops connected to without problems at our previous location, but since moving here the Macs will not connect to the NAS. All other devices on the network are connecting well. I have had a long tiring interchange with the Synology tech people including a 2.5 hour screen share session, and their conclusion was that something is preventing it connecting using IPv4, but it will connect with IPv6. I’m not tech savvy enough to understand this. If I use the NAS’s IPv6 address I can connect to the NAS on a browser, but I still can’t connect with Time Machine, so I can't currently back up our computers to the NAS and I am getting worried.
The Synology techs said to contact the Netgear tech people to ask whether there are any settings in the Nighthawk M2 which would enable the NAS to connect using IPv4?
Help! Any advice greatly appreciated.