I’ve had the same problem all week. I can’t get online at all. I have hard reset my Xbox numerous times and it still isn’t working. It has been a reoccurring problem every since the reach update. I’ve had every halo and never had this many problems with online. 343 please fix your s**t
I recommend resetting your router as well. Run the multiplayer and connection test in xbl settings. If you can get a wired connection with open nat.