Looks like Xbox Live is down across platforms per the official Xbox Support Twitter feed. Started around 4:00 PM EST and is since continuing, with users getting error code 0x87DD0006 when attempting to sign into our services across devices:
This will impacts Xbox One, Xbox 360, Windows 10 games and Xbox on devices (such as phones and tablets). The last update was that the issue appears to have been identified, but yet to be rectified. Keep an eye on the Twitter feed or visit the
Xbox Live Status page for updates.