Question for the network guru's. My Asus RT-AC1900P appears to have died. It was setup behind an AT&T Modem so that I could use the VPN functionality of the RT-AC1900P. I also have a Synology DS218+ that has a built-in VPN Server. Part of the setup on the Synology requires that I forward a port on my AT&T Modem to the Synology, is this deemed safe or should I replace my Asus router?