If you were trying to access certain porn websites unsuccessfully over the past couple of days, please stop blaming your Airtel connection and direct all of your frustration and pent-up anxiety towards Iran.

Yes, in an extreme effort to block porn websites from the country, Iran ended up turning certain fundamental Internet knobs that it should have left unturned, because it ended up blocking Internet traffic from countries like India, Russia and even Hong Kong and Indonesia.

How’s this possible? How can one country end up curtailing the Internet in another country altogether?

Well, it’s an age-old trick that governments exploit in a fundamental frailty of the Internet, exposing its dangers in the process. It all starts from confusing the Border Gateway Protocol or BGP, a method used by different ISPs (Internet Service Providers) to exchange routing information for website requests.

When you type www.google.com in your Web browser, your website request actually bounces through different servers, known as Domain Name Servers that maintain the directory of website names and their unique IP addresses -- Google.com’s address, for instance, is 216.58.196.110. What BGP does is acts as a traffic policeman directing ISP’s requests, translating addresses and fulfilling website queries.

But BGP is also insecure and a telco can introduce false routes to confuse ISPs and misdirect website queries, which is exactly what Iran Telecom did a few days ago, in order to prohibit hundreds of porn websites from being accessed through the country.

This step by Iran -- of altering BGP -- ended up affecting several ISPs. According to The Verge, Internet traffic from Bharti Airtel in India, Russia’s RETN, Indonesia’s Telekomunikasi and Hong Kong’s Hutchison, which was passing through Iran Telecom, ended up being misdirected unintentionally, resulting on these websites being blocked not only in Iran but also in India, Russia, Hong Kong and Indonesia -- for people who tried accessing them through the affected ISPs in these regions.

This is a stark reminder of the unintended consequences of Internet blocks, as nothing truly can be blocked on the Internet for long. BGP’s vulnerable and ageing framework is also a cause for concern, and hopefully it’s being replaced with a newer, more secure protocol soon.