The problem involves the routers used by every organization and company that owns a block of IP addresses. Those routers communicate constantly with other routers, updating their internal information -- often upwards of 400,000 entries -- on the best way to reach other networks using a protocol called Border Gateway Protocol (BGP).

BGP enables routers to find the best path when, say, a network used to retrieve a web page from South Korea is not working properly. Changes in that routing information are distributed quickly to routers around the world in as few as five minutes.

But the routers do not verify that the route "announcements," as they are called, are correct. Mistakes in entering the information -- or worse yet, a malicious attack -- can cause a network to become unavailable.

It can also cause, for example, a company's Internet traffic to be circuitously routed through another network it does not need to go through, opening the possibility the traffic could be intercepted. The attack is known as "route hijacking," and can't be stopped by any security product.

When routing problems erupt, "it's very difficult to tell if this is fat fingering on a router or malicious," said Joe Gersch, chief operating officer for Secure64, a company that makes Domain Name System (DNS) server software. "It could be a trial run for cyberwarfare."