• Saw this in the log just now.

    nginx: 2016/03/20 15:22:55 [error] 89386#0: *850 limiting connections by zone "addr", client:, server: , request: "GET /filestreamingservice/files/bc6c4a54-f4f6-4f9a-80e1-b1d31bd1e1e8?P1=1458503334&P2=301&P3=2&P4=D0XhXEveNaC%2f4cm%2b4WHp4%2bRe46ZiwWZ5%2f3vy0pOi8dQ%3d HTTP/1.1", host: "tlu.dl.delivery.mp.microsoft.com"

    There were a few of them.

  • Rate limiting of captive portal clients who are making too many requests to the portal. Probably some background process hammering away trying to get to the Internet on a system that isn't authenticated.