Office 365 is widely used between many customers. Some of them happen to manage all the Internet connections through a Cisco ASA , not the fancy ASA-X with Firepower , just the plain old 5510.
I was asked to allow Office 365 traffic, looks easy huh?
Step 1: know your enemy After some Google-fu I found Microsoft kindly provides an update list of the IP/subnet/URLs necessary to access various services including Office 365, Lync, OneNOte etc.
