In a weird turn of events, Pakistan’s attempts to block its citizens from accessing Google-owned YouTube wound up sending the video-sharing site into a “black hole” and exposing some fundamental weaknesses of the Net architecture.

It’s not clear what YouTube video spurred the Pakistani action. Leading contenders include a film by Dutch anti-Islamic politician Geert Wilders and the incendiary political cartoons featuring the prophet Muhammad published by Dutch newspapers in 2005. The newspapers recently republished the cartoons in solidarity with the cartoonist, whose life was threatened in a plot discovered by Dutch authorities.

Whatever the reason, the Pakistan Telecommunications Authority issued an order to Pakistani ISPs to block YouTube. The nation’s largest ISP, Pakistan Telecommunications Corp. Ltd. (PTCL) took steps to send all requests from Pakistan for YouTube into a “black gap.” But, apparently inadvertently, the ISP hijacked YouTube’s IP addresses, effectively shutting down the site for users around the world for several hours.

Google Still Investigating

“Traffic to YouTube was routed according to erroneous World Wide Web protocols, and many users around the world could not access our site,” Google announced after working around the problem. “We have determined that the source of these events was a network in Pakistan. We are investigating and working with others in the Web community to prevent that from happening again.”

BBC reporter Darren Waters, who did some of the early reporting on the story, wrote in a blog, “There will definitely be some fallout from that. It would seem that all it takes to hijack a Web site globally is for a telecoms firm to instruct its ISPs that they now run a domain, and for one of those ISPs to announce that globally. So that other ISPs follow suit in a piggyback chain of confusion.”

What happened precisely? The reply has to do with some fairly low-level details…

Orginal post by Top Tech News