How Syria Severed The Internet
And How Easy Would That Be For Other Countries?
A new analysis by Cloudfare
explores how it was so easy for Syria to simply disconnect the Internet last week. According to the firm, there are four physical fiber lines running into and out of Syria, three underwater and one over land in Turkey. Though the Syrian Minister of Information claimed all four lines were severed by "terrorists," Cloudfare argues that this is unlikely, and that the Internet shut off was accomplished instead through updates in router configurations, not through physical means:
Beginning at 1026 UTC, routes were withdrawn for PCCW. The routing shifted primarily to Turk Telekom. Routes to Telecom Italia and TATA were also withdrawn, but has less of an impact. Then, at 1028 UTC, routes were withdrawn for Turk Telekom. After that, Syria was effectively cut off from the Internet. (Note that the remaining path that appears to be present in the video is an anomaly. We have confirmed that it is not actually active.)
While we cannot know for sure, our network team estimates that Syria likely has a small number of edge routers. All the edge routers are controlled by Syrian Telecommunications. The systematic way in which routes were withdrawn suggests that this was done through updates in router configurations, not through a physical failure or cable cut.
directs our attention to some analysis by Renesys
examining just how easy it would theoretically be for most countries to sever connectivity. Obviously, it's easier for a country to be shuttered when just one or two telcos control all the international connections -- especially when they're a state run monopoly.