Tell HN: DNS censorship has started in Hong Kong

22 points

6 years ago

Internet censorship has historically been rare in Hong Kong [0], as opposed to its ubiquity in mainland China.

However, after some friends there mentioned difficulty accessing some websites, I decided to check whether recent events have led to an increase in Internet censorship. I surveyed the top 10,000 websites based on Alexa data.

The following 13 names (in Alexa rank order) reliably fail to resolve (return SERVFAIL) using any Hong Kong ISP's DNS server, and using major external DNS providers via Hong Kong ISP connections [1], but reliably successfully resolve outside of Hong Kong (or within Hong Kong when using a VPN or other technology to securely tunnel the DNS traffic):

  dol.gov
  osha.gov
  army.mil
  rapidshare.com
  yell.com
  uscg.mil
  news.abs-cbn.com
  arl.army.mil
  mundialreguas.com.br
  economictimes.com
  temizliknasilyapilir.com
  starmusic.abs-cbn.com
  publicbankinginstitute.org

[0] https://en.wikipedia.org/wiki/Internet_censorship_in_Hong_Kong

[1] This suggests that ISPs are intercepting port 53 traffic to external DNS (such as CloudFlare's 1.1.1.1 or Google's 8.8.8.8) and spoofing a SERVFAIL reply, or that all tested external DNS providers have been compelled to also implement the censorship.

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