Update: I have previously commented (3x) on this issue. Essentially the same experience as most of the posters in the thread. Followed all the Bungie recommendations to the letter. Also tried two different high-performance wired routers (Ubiquiti ERL (with miniupnpd2 UPNP, the best open-source UPNP implementation) and a Netgear Nighthawk X4S). My ISP is Comcast (Blast). All three XBox Ones consistently report Open NAT, and we have never had any problem with local fireteams on any game other than Destiny. We could all also play Destiny at the same time, no problems, just not with each other. Our Destiny local fireteam problems started back in July, just like most of the posters. I had been broken since. Always the immediate "Unable to join target..." error. But a couple of weeks ago, it started working, and has been bulletproof since. There was nothing that I did on my end. We tried it a few days after RoI came out, just in case it worked, and it did and still does without a hiccup. So, to speculate... it seems pretty apparent that the root of this problem is in the Destiny server implementation, in the way that it allocates/load-balances player traffic. Sometimes you get lucky and your local fireteam players land on the same (or otherwise co-hosted or compatible) servers, and it works... and sometimes (most of the time) not. Which is why all the crazy spam-the-join-button, quit-and-relauch, simultaneous-join, etc. work-around stories appear, but none are reliable/repeatable. I also suspect that there may be some elves working in the background at Bungie Ops that are able to manually provision load/server-allocation based on the Gamertags we report. This may be dependent on geography, network provider and datacenter allocations, and many other factors. Which may explain why they can fix some of us, but maybe not all of us. And, also why there is no console patch that can fix it and it doesn't show up in the release notes. I am reporting this because I expect that a lot of people that have experienced the local fireteam problem and reported it here, may have had their problem resolved. Most happily go on with their lives, and don't report the resolution here. I am a networking engineer, and have had to deal with problems like this from the other side. It's hard, and I feel for the Bungie Ops team. But, the lack of communication and transparency on this is really problematic. And there is no excuse for it. Those of us that have bought multiple consoles, multiple copies, DLCs, etc. are probably among Bungie's best net-promoters and they are doing irreparable damage to their reputation with their silence and perceived indifference. WAKE UP and OWN UP! Good luck to all, Dave