Hi Daniele,
I’m currently switching from Sunrise to UPC. After receiving the modem yesterday I have been trying to migrate the Synology DDNS access to the UPC device. For the DDNS service to work, port 53 needs to be forwarded. First of all, the Giga Connect Box refuses to forward this port and furthermore does the connect box seem to be in IPv6 mode. Forwarding port 53 is something that can be done with pretty much every other operator. Therefore I kindly ask you to provide the necessary steps and , if required, make the neccessary configurations to allow for forwarding of port 53.
Best regards.
Fabian