i think the most recent fiasco took down many thousands of pcs. not pretty from a PR standpoint. i am fortunate that i didnt have any problems where i work. they are definitely getting flak lately for some azure services outages and windows updates problems that appear to be related to a quicker development pace that doesnt include enough time for testing prior to release.
that is probably the least of their worries. 1500 pcs pulling updates is a drop in the bucket. there are probably many more times that in just WSUS servers getting updates; never mind single pcs.
there are a lot of IPs used for windows updates, as they are surely spread around on a lot of publicly available servers. see this thread:
http://social.technet.microsoft.com...r-windows-server-2008?forum=winserversecurity
for some reason my boss insists on having our 200 work pcs run windows updates over the internet instead of from a WSUS server. despite my having set up a WSUS server for new pc deployments anyway. /facepalm