The Backblaze client sends data to the Backblaze datacenter. The Backblaze datacenter servers are located at IP addresses in the following ranges (these are in "subnet notation"):
All Backblaze servers use the *.backblaze.com or *backblazeb2.com domains, so it may be easiest to whitelist the appropriate domain.
Last updated: July 2018
NOTE: Backblaze is always adding more computers and so the following information WILL CHANGE in the future!