Outages that made Microsoft Azure and multiple Microsoft cloud services widely unavailable for 90 minutes on January 25 can be traced to the cascading effects of repeated, rapid readvertising of BGP router prefixes, according to a ThousandEyes analysis of the incident. The Cisco-owned network intelligence company traced the Microsoft outage to an external BGP change by Microsoft that affected service providers. Read more about network and infrastructure outages in our top 10 outages of 2022 recap.