How Pakistan knocked YouTube offline (and how to make sure it never happens again)
YouTube becoming unreachable isn't the first time that Internet addresses were hijacked. But if it spurs interest in better security, it may be the last.
A high-profile incident this weekend in which Pakistan's state-owned telecommunications company managed to cut YouTube off the global Web highlights a long-standing security weakness in the way the Internet is managed.
After receiving a censorship order from the telecommunications ministry directing that YouTube.com be blocked, Pakistan Telecom went even further. By accident or design, the company broadcast instructions worldwide claiming to be the legitimate destination for anyone trying to reach YouTube's range of Internet addresses.
The security weakness lies in why those false instructions, which took YouTube offline for two hours on Sunday, were believed by routers around the globe. That's because Hong Kong-based PCCW, which provides the Internet link to Pakistan Telecom, did not stop the misleading broadcast--which is what most large providers in the United States and Europe do.
This is not a new problem. A network provider in Turkey once pretended to be the entire Internet, snarling traffic and making many Web sites unreachable. Con Edison accidentally hijacked the Internet addresses for Panix customers including Martha Stuart Living Omnimedia and the New York Daily News. Problems with errant broadcasts go back as far as 1997.
