We're seeing a large increase in inbound traffic levels today.

Appears to be coming in both over peering links and internationally. Right now it appears to be Microsoft related.

An AKL-IX graph shows it well - http://monitor.akl-ix.nz/cacti/graph.php?local_graph_id=14&rra_id=all

Or the MS port: http://monitor.akl-ix.nz/cacti/graph.php?action=view&local_graph_id=137&rra_id=all

Does anyone else have more information to add as to what MS patches or similar are causing this? And over what borders this traffic is entering their networks?