On November 12, 2018, a small ISP in Nigeria made a mistake while updating its network infrastructure that highlights a critical flaw in the fabric of the Internet. The mistake effectively brought down Google one of the largest tech companies in the world for 74 minutes. The Internet is broken up into a number of autonomous systems (ASs) Each AS is assigned an autonomous system number (ASN) by the Internet Assigned Numbers Authority. Big companies like Google also maintain their own border routing infrastructure and have their own ASN.”]
Source: https://www.darkreading.com/cloud/how-a-nigerian-isp-accidentally-hijacked-the-internet