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July 5, 1999
Srikant Sreenivasan and Priya Ganapati
Traditionally, Indian government has shown little respect for the power of the Internet. Now they think that they can censor it!
Last week India's international Internet gateways blocked access to http://www.dawn.com, the online news site of Pakistani daily Dawn.
Who ordered the blockade in the first place?
It is also the largest Internet service provider in the country and controls the international Internet gateways that the ISPs in India use.
Last week its gateways blocked access to the news site of Dawn, one of the most respected newspapers of Pakistan.
VSNL Chief Public Relations Officer G C Banik told Rediff "VSNL has not blocked it (Dawn site) yet. We have not closed it." When it was pointed out that surfers from India are not able to reach the Dawn site, Banik suggested that Rediff could countercheck with the technical department or the CMD himself.
But VSNL Acting Chairman and Managing Director Amitabh Kumar told Rediff "Yes. We have blocked the site. But it is under instruction from higher authorities." When asked about the legality of the order, Kumar said "We have done it under the authority given to us by the Indian Telegraph Act."
However, Kumar refused to either confirm or deny reports that the Dawn site's blockade was ordered directly by the Prime Minister's Office.
When Kumar was told how Rediff and surely many other surfers could easily bypass the blockade with methods like use of 'anonymiser services', he said, "Our personal opinion does not matter. We are doing it under instructions from higher authorities."
Blocking a site: a technology primerEvery site on the Internet is identified by a unique 'domain name'.
An example of a domain name is http://www.rediff.com. But computers do not understand English language names like http://www.rediff.com. That is why every domain name has to be associated with a numerical address like http://18.104.22.168. This numerical address is call the 'Internet protocol' address or the IP address.
Whenever you type in http://www.rediff.com, the computer checks a directory that relates the domain names with their respective IP addresses. The directory that does this job is called a 'domain name system' server or a DNS server.
The IP address of Dawn's Web server is 22.214.171.124. Like Rediff, you can verify this by 'nslookup', a simple Internet command for name server look-up.
Once the DNS server has thrown up the IP address of a site, the surfer's request is forwarded to the relevant IP address and the Web page gets delivered.
But the request has to pass through the country's international gateway. VSNL controls these international gateways in India.
That is why VSNL has been able to attempt blockade of the Dawn site. All it needs to do is simply add Dawn's IP addresses to a special 'deny' list on the gateway routers.
Immediately, all further requests to the banned IP address will be denied.
How to break the blockadeNow that you understand the technology behind blocking access to a site, the more astute amongst you must have realised that to circumvent this censorship all that one has to do is to access the 'blocked' site through some anonymiser service.
Anonymiser services are sites that fetch a Web page on your behalf and redirect them to you.
This means that the VSNL gateway can't tell what site you are really looking at because effectively, it believes you are communicating with only the anonymiser site.
This is because VSNL's gateway routers see the IP address of only the anonymiser service and not the IP address that has been put on the deny list.
Links to several such anonymiser services are given at the end of this article.
Now, all you have to do to view a 'blocked' site is to visit an anonymiser service and enter the address of the blocked site that you need to see. And bang! There you are, the site comes through without a hitch. Only a bit slower though.
Search and ye shall find:
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