Nearly half of Japan briefly lost internet access when Google made a small error. The search giant accidentally botched a Border Gateway Protocol (BGP) when it added a number of falsely announced peer prefixes sent to Verizon.
This was because a large chunk of IP addresses that were available for internet traffic to be routed through Google, actually belonged to Japanese Internet Service Providers. So a large amount of traffic that was meant for Japan was suddenly sent towards Google.
Because Google is not an Internet Service Provider (ISP) and isn't meant to route traffic, so all of that traffic destined for Japan was basically just sent to nowhere.
As a result, shortly after the faulty rerouting request happened, numerous users using ISPs like NTT Communications and KDDI Corp. were unable to connect to the web, or had their internet speed significantly lowered.
A Google spokesperson said that "We set wrong information for the network and, as a result, problems occurred. We modified the information to the correct one within eight minutes. We apologize for causing inconvenience and anxieties (among Internet users)."
Google realized about the mistake within minutes, but the effects led to hours of internet problems in Japan. In fact, the impact was huge that Japan's Internal Affairs and Communications Ministry initiated an investigation into the issue.
The mistake affected industries like finance, where online trading was halted. Transportation like the East Japan Railway Co. people were't able to buy tickets or board trains. Clients of Resona Bank, Saitama Resona Bank and Kinki Osaka Bank said that they had trouble logging in to their accounts, and also did customers of online banker Jibun Bank Corp. and Rakuten Securities Inc.
East Japan Railway Co. (JR East) said some users of its Suica mobile payment system complained they weren't able to use the service, preventing them to buy tickets and board the trains. Visitors to JR East's website also experienced poor connections, including those who were trying to use the online reservation system.
Nintendo Co. also said on its website that some Switch, Wii U and 3DS clients started complaining about poor connectivity at about 12:25 p.m.
About seven million people in Japan were affected.
Google realized the mistake and assuming full responsibility for what happened during the blackout.
In another similar problem, earlier in 2017, a block on porn in Iran broke the internet in Hong Kong.
