Domain Name System

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The Domain Name System (DNS) resolves domain names to IP-adresses.

Every computer on the Internet has an unique address (a little bit like a telephone number). These are 4 numbers from 0 to 255 separated with a dot, for example 85.13.138.4 is the IP-address for cship.org.

Because of remembering such a number is very difficult the DNS was invented. This service maps an URL to it it's IP-address. If you type cship.org into your browser the request is send to the DNS-server that was automatically given to you by your ISP on dialing into the Internet. A lot of addresses are already cached so the DNS-server sends the IP-address for the URL back to you. If the DNS-server has no cached information on the site requested by you he asks one of the 13 root servers which know all addresses. If the DNS server from your provider is censoring he just refuse to send you the real IP-address; he sends you nothing or an IP from a "sorry" website.

This is used for example from some german providers. It is a very cheap and easy censoring method and the same is true for bypassing it. To bypass this censorship method you can use another DNS server or try almost all other bypass methods.

It is also possible to tunnel normal web access over a DNS tunnel. You can check if you have problems with your DNS-Server by visiting the URL http://208.67.219.60/. You should see a OpenDNS status page. If you see it but no other "normal" website like http://www.google.com/, than you can access the Internet, but your DNS server is not working. Then enter one of the servers below in your client.

Public DNS servers from Google (without any filters):[edit]

Public DNS servers from OpenDNS (they may block porn and malware sites):[edit]

Public DNS server from DynDNS (they may block malware sites):[edit]

  • 216.146.35.35 (resolver1.dyndnsinternetguide.com)
  • 216.146.36.36 (resolver2.dyndnsinternetguide.com)
  • instructions to use

Public DNS servers from censurfridns.dk (without any filters):[edit]

  • 89.233.43.71 / 2002:d596:2a92:1:71:53::
  • 89.104.194.142 / 2002:5968:c28e::53
  • more info

Public DNS servers from DNS Advantage (they may block malware sites):[edit]

  • 156.154.70.1 (rdns1.ultradns.net)
  • 156.154.71.1 (rdns2.ultradns.net)
  • instructions to use
  • you can also use 156.154.70.22 and 156.154.71.22 which are advertised by Comodo

Public DNS servers from FoolDNS (blocks ads and malware)[edit]

Weblinks:[edit]