We have family members in our home that playing Destiny. My account only works when using the factory default settings with no port forwarding in the router. My girl's is completely set for port forwarding and her son's is on wifi - factory default. It is how we have to set it up for us all to play without issues. On her account, she does on occasion receive a disconnect error and a review of the router port information shows that the ISP automatically set two additional XBOX port forwards on to IP's not used in the house. Deleting these allows for her to play issue free. Each XBOX maintains it's own IP historically. If you are experiencing a disconnect when you are port forwarded, you may want to take a look at your router and see if this happens to you. We have no idea why this happens to her and have a secure router.