Tag Archives : routing November 2010

China Hijacks 15% of Internet Traffic?

By: Craig Labovitz -

On Wednesday, the US China Economic and Security Review Commission released a wide-ranging report on China trade, capital markets, human rights, WTO compliance, and other topics. If you have time to spare, here is a link to the 324 page report.

Tucked away in the hundreds of pages of China analysis is a section on the Chinese Internet, including the well-documented April 8, 2010 BGP hijack of several thousand routes (starting on page 244).

To review, shortly around 4am GMT on April 8th a Chinese Internet provider announced 40,000 routes belonging to other ISPs / enterprises around the world (though many were for China based companies). During a subsequent roughly 15 minute window, a small percentage of Internet providers around the world redirected traffic for a small percentage of these routes to Chinese address space. RIPE provides a link to a list of some of these prefixes (as well as indicating the impact on European carriers was minimal) and Andree Toonk and his colleagues at BGPmon have a nice synopsis at the BGPMon blog.

Following shortly on the heels of the China hijack of DNS addresses in March, the April BGP incident generated a significant amount of discussion in the Internet engineering community.


panic

Any corruption of DNS or global routing data (whatever the motive) is a cause of significant concern and reiterates the need for routing and DNS security. But in an industry crowded with security marketing and hype, it is important we limit the hyperbole and keep the discussion focused around the legitimate long-term infrastructure security threats and technical realities.

So, it was with a bit of a surprise that I watched an alarmed Wolf Blitzer report on prime time CNN about the China hijack of “15% of the Internet” last night. A bit less diplomatic, a discussion thread on the North American Network Operator Group (NANOG) mailing list called media reports an exaggeration or “complete FUD”. Also on the NANOG mailing list, Bob Poortinga writes “This article … is full of false data. I assert that much less than 15%, probably on the order of 1% to 2% (much less in the US) was actually diverted.”

If you read the USCESRC report, the committee only claims China hijacked “massive volumes” of Internet traffic but never get as specific as an exact percentage. The relevant excerpt from the report below:



The USCESRC cites the BGPMon blog as the source of data on “massive traffic volumes”. But curiously, the BGPMon blog makes no reference to traffic — only the number of routes.

You have to go to a National Defense interview with Dmitri Alperovitch, vice president of threat research at McAfee, to first come up with the 15% number. Several hundred media outlets, including CNN, the Wall Street Journal, Time Magazine and many more picked up this interview and eagerly reported on China’s hijack of “massive Internet traffic volumes of 15% or more”.

Now certainly, diverting 15% of the Internet even for just 15 minutes would be a major event. But as earlier analysis by Internet researchers suggested, this hijack had limited impact on the Internet routing infrastructure — most of the Internet ignored the hijack for various technical reasons.

And indeed, ATLAS data from 80 carriers around the world graphed below shows little statistically significant increase due to the hijack on April 8, 2010. I highlight April 8th in yellow and each bar shows the maximum five minute traffic volume observed each day in April going to the Chinese provider at the center of the route hijack.


china hijack

While traffic may have exhibited a modest increase to the Chinese Internet provider (AS23724), I’d estimate diverted traffic never topped a handful of Gbps. And in an Internet quickly approaching 80-100 Tbps, 1-3 Gbps of traffic is far from 15% (it is much closer to 0.015%).

In fairness, I should note that I don’t know how Mr. Alperovitch obtained his 15% number (the article does not say) and a hijack of 40k routes out of a default-free table of ~340K is not far from fifteen percent. But of course, routes are different from traffic. I also add that both China denied the hijack and some Internet researchers suspect the incident was likely accidental.

The global BGP Internet routing system is incredibly insecure. Fifteen years ago, I wrote a PhD thesis (link available here) using experiments in part capitalizing on the lack of routing security. My research injected hundreds of thousands fake routes (harmless!) into the Internet and redirected test traffic over the course of two years. A decade or more later, none of the many BGP security proposals have seen significant adoption due to a lack of market incentives and non-legitimate routes still regularly get announced and propagated by accident or otherwise. Overall, the Internet routing system still relies primarily on trust (or “routing by rumor” if you are more cynical).

We need to fix Internet infrastructure security, but we also need to be precise in our analysis of the problems.

UPDATE: Additional discussion and statistics on the incident are now available in a follow-up blog at /asert/2010/11/additional-discussion-of-the-april-china-bgp-hijack-incident.

- Craig