Reports have now verified that Eqypt has cut off access to the internet amid political protests. Renesys, an internet monitoring firm based in Manchester, New Hampshire, calls the situation "an action unprecedented in Internet history," according to a company blog post.
The development of an internet "kill switch" that our own government could use in the case of a national emergency has been proposed here in the U.S., and if we take a look at how Egypt has already flipped its own kill switch, it may give us more insight into how such a system would work here.
The Basics of an Internet Connection
On the simplest of levels, your computer connects to the internet through an internet service provider (ISP)—Comcast, Time Warner, Qwest, Verizon, etc.—and your service provider either connects directly to all the other internet service providers around the world or to a larger internet service provider that then connects to all the others.
When you open up your web browser and type a domain name into the address bar—say Time.com, for instance—your service provider sends a lightning-quick request to whichever service provider Time.com uses to make its web pages publicly available on the internet.
The computer that holds all of Time.com’s web pages sends a response back through its internet service provider basically saying, "Yes, we’re online. Here’s the web page you requested."
The Border Gateway Protocol
In order for ISPs to establish broader connections between the computers on their networks and the rest of the computers on the internet, traffic is routed through the Border Gateway Protocol (BGP). Egypt’s ISPs have a certain amount of machine-readable internet protocol (IP) addresses that are used to identify connected computers across the internet, and the BGP makes the active IP addresses visible to the rest of the world to facilitate connections.