This major internet routing blunder took A WEEK to fix. Why so long? It was IPv6 – and no one really noticed

When you meant to type /127 but entered /12 instead

Last week, an internet routing screw-up propagated by Verizon for three hours sparked havoc online, leading to significant press attention and industry calls for greater network security.…

via The Register - Data Centre: Networks
http://go.theregister.com/feed/www.theregister.co.uk/2019/07/02/ipv6_routing_error/