How Egypt switched off the Internet
A fascinating technical look at how Egypt shut off its Internet connection to the rest of the world:
…the signs are that the Egyptian authorities have taken a very careful and well-planned method to screen off Internet addresses at every level, from users inside the country trying to get out and from the rest of the world trying to get in.
“It looks like they’re taking action at two levels,” Rik Ferguson of Trend Micro told me. “First at the DNS level, so any attempt to resolve any address in .eg will fail — but also, in case you’re trying to get directly to an address, they are also using the Border Gateway Protocol, the system through which ISPs advertise their Internet protocol addresses to the network. Many ISPs have basically stopped advertising any internet addresses at all.”
Essentially, we’re talking about a system that no longer knows where anything is. Outsiders can’t find Egyptian websites, and insiders can’t find anything at all. It’s as if the postal system suddenly erased every address inside America — and forgot that it was even called America in the first place.
A complete border shutdown might have been easier, but Egypt has made sure that there should be no downstream impact, no loss of traffic in countries further down the cables. That will ease the diplomatic and economic pressure from other nations, and make it harder for protesters inside the country to get information in and out.
Ferguson suggests that, if nothing else, the methods used by the Egyptian government prove how fragile digital communication really is.
“What struck me most is that we’ve been extolling the virtues of the Internet for democracy and free speech, but an incident like this demonstrates how easy it is — particularly in a country where there’s a high level of governmental control — to just switch this access off.”
