Facebook and China

There have been some reports suggesting that Facebook may be blocked in China, however, Facebook is not blocked in China. In fact, I experienced Facebook outages myself — from Canada — on July 1 too. At therecent Global Voices Summit I gave a presentation on detecting Internet filtering. While it is sometimes easy to detect, sometimes it is not — often there are alternative explanations.

www.facebook.com (and zh-cn.facebook.com) resolves to a variety of IP addresses,, and and a few of them. DNS servers in China and resolving www.facebook.com properly and these IP addresses are accessible when directly accessed from China.

However, while facebook is loading you have probably seen a domain like this, static.ak.fbcdn.net or like this static.ak.facebook.com, flash by in your browser’s status bar. Domains such as these resolve to IP addresses assigned to Akamai. Akamai is a mirroring service that has servers all over the world so depending on where you are you’ll be accessing the same content but from a different server.

One scenario is that there was some temporary issue with Akamai.

Another is that Chia may have blocked one of Akamai’s IP addresses. (Pakistan, for example, once disrupted access to numerous sites because they blocked portions of the Akamai network. Apparently, they did not realize that in trying to a few sites on Akamai they ended up blocking thousands of the world’s most popular sites.)

I tested a variety of Akamai IP addresses that Chinese DNS servers resolved the “static” facebook domains too and all were acessible from multiple points in the country.

One comment.

  1. I am in Shanghai. I cannot access FB since yesterday!

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