20 Nov 2015

Google Services Temporarily Cut Off Due To Hathway’s Incorrect Traffic Routing

The original design of Internet and its protocols presupposes existence of mutual trust and this at times also cause troubles. In the initial age of Internet, there were very few Internet protocol addresses and they use to communicate with each other directly. There was little reason for abuse or distrust among these IP addresses and their owners. There were also no fears of impersonation and IP spoofing as well.

However, as the Internet and these protocols grew, they became more unstable and untrustworthy. Now if we send something in plain text, chances are great that such plain text information maybe intercepted and misused. Nevertheless, networks and systems still need to trust each other to make the Internet function in a speedier manner. If one system or service provider falters, the services of other may be hampered.

In one such incidence, users around the world were not able to access Google’s service for a short period of time due to a technical glitch. Users were cut off due to the routing leak from Indian broadband Internet provider Hathway. The leak is similar to a 2012 incident caused by an Indonesian ISP, which took Google offline for 30 minutes worldwide.

Routing leaks occur when a network provider broadcasts all or part of its internal routing table to one or more peered networks via the Border Gateway Protocol (BGP) causing network traffic to be routed incorrectly. In the present case Hathway’s boundary router incorrectly announced routing data for over 300 network prefixes belonging to Google to the Internet backbone via its provider Bharti Airtel. Bharti in turn announced these routes to the rest of the world and a number of international ISPs accepted these routes.

Now why would Google rely upon Hathway for its services? This is because Hathway peers with Google to provide better speed to Google’s cloud, directing traffic to the closest Google data centers. That peering is a private network connection. As a result, when the routing table was accidentally broadcast to the world instead of just to Hathway’s customers, much of the world was trying to access Google via Mumbai, through Hathway, instead of over the public Internet.

By design users cannot access Google services with incorrect route information till it is rectified or routed correctly.