Tornando alle cose serie: oggi qualcuno ha spento Internet in Siria.
The Syrian Minister of Information is being reported as saying that the government did not disable the Internet, but instead the outage was caused by a cable being cut. Specifically: “It is not true that the state cut the Internet. The terrorists targeted the Internet lines, resulting in some regions being cut off.” From our investigation, that appears unlikely to be the case.
To begin, all connectivity to Syria, not just some regions, has been cut. The exclusive provider of Internet access in Syria is the state-run Syrian Telecommunications Establishment. Their network AS number is AS29386. The following network providers typically provide connectivity from Syria to the rest of the Internet: PCCW and Turk Telekom as the primary providers with Telecom Italia, TATA for additional capacity. When the outage happened, the BGP routes to Syrian IP space were all simultaneously withdrawn from all of Syria’s upstream providers. The effect of this is that networks were unable to route traffic to Syrian IP space, effectively cutting the country off the Internet.
Syria has 4 physical cables that connect it to the rest of the Internet. Three are undersea cables that land in the city of Tartous, Syria. The fourth is an over-land cable through Turkey. In order for a whole-country outage, all four of these cables would have had to been cut simultaneously. That is unlikely to have happened.