We’ve been asked all day to comment on the potential for Internet shutdowns in Turkey. At this point, Renesys observes no significant changes in Turkey’s Internet routing, no significant outages affecting the routing of Turkey’s networks, no reduction in the number of inbound active measurements to Turkish hosts within the country from our infrastructure [...]
Update (15:26 UTC, 15 May): Routes to Syrian networks have been restored, at 18:26 Damascus time. Outage duration: 8h25m
Update (14:20 UTC, 15 May): Plot of latency measurements to Syrian hosts from various locations, indicating that replies stopped returning shortly after 7am UTC, aligned with the withdrawal of routes to Syrian networks. (Click image for details)
Update (07:30 UTC, 15 May): Syrian Internet down again since 07:01 UTC (10:00 Damascus time), Wednesday, 15 May 2013. Syrian news agency reports that they’re working to fix. Potentially related to forthcoming UN decision today?
Update: Syrian Internet has returned. Outage lasted 19.5 hours, from 18:45 UTC May 7th to 14:13 UTC May 8th.
As we write, the Syrian people are still disconnected from the global Internet at the most fundamental level, nearly all of their paths withdrawn from the global routing table. Since 18:45 UTC on May 7th, Renesys hasn’t seen a flicker of activity. We haven’t been able to successfully send a ping or a traceroute to any host inside Syria. Government websites, universities, domain name servers, core infrastructure routers, banks, businesses, DSL customers, smartphones: all silent.
As I look back at what we’ve written about Internet outage over the years, I see a sort of evolution in our perspective. We’ve covered Internet failures due to war, politics, censorship, central planning, earthquakes, hurricanes, cable cuts, business disputes, terrorism, undersea mud volcanoes, and (perhaps) cyberwarfare.
In the early days, we reported each outage breathlessly, shocked that the Internet could fail in such spectacular ways. If you look around the web this morning, you’ll see a lot of that same shock-and-awe reporting from companies who are just discovering the fragilities visible in Internet data.
Sometimes, it takes a real disaster to create something genuinely new. March 2013 was a month of disasters in the Middle Eastern, South Asian, and East African Internet, with major submarine cable cuts affecting SMW3, SMW4, IMEWE, EIG, SEACOM, and TE-North.
One of the “genuinely new” Internet traffic paths that emerged in response is a counterintuitive terrestrial route, linking the ancient Indian Ocean trade empire of Oman with the Internet markets of Western Europe, by way of Iran, Azerbaijan, and the Russian Caucasus. As we’ll see, its effects are now being felt across the region, from Pakistan, to Gulf states like Bahrain and Oman, to Kenya.
The EPEG (Europe-Persia Express Gateway) consortium was actually born in June 2011, as an alternative to the congested, politically uncertain Suez transit corridor. EPEG links together existing fiber routes from the Iranian, Azeri, and Russian incumbents, connected to Cable and Wireless’s network to approximate a Great Circle route to Frankfurt. With the aid of one final submarine hop across the Strait of Hormuz to Muscat, EPEG promised to deliver a major new low-latency, high-capacity terrestrial route to carry the Gulf states’ traffic to Europe.
Renesys confirms a largely complete restoration of the Syrian Internet this morning, starting at 14:32:10 UTC (16:32 local time in Damascus).
Transit providers for the full prefix set do not appear to be significantly changed, with Internet service being provided post-restoration by Telecom Italia, Tata Communications, Turk Telecom, and PCCW.
|Here’s a view of live Syrian prefix counts during the outage and restoration, from 29 November to 1 December:|
How hard is it to disconnect a country from the Internet, really?
That’s the number one question we’ve received about our analysis of the Egyptian and Syrian Internet blackouts, and it’s a reasonable question. If the Internet is so famously resilient, designed to survive wars and calamities, how can it fail so abruptly and completely at the national level?
The key to the Internet’s survival is the Internet’s decentralization — and it’s not uniform across the world. In some countries, international access to data and telecommunications services is heavily regulated. There may be only one or two companies who hold official licenses to carry voice and Internet traffic to and from the outside world, and they are required by law to mediate access for everyone else.
Under those circumstances, it’s almost trivial for a government to issue an order that would take down the Internet. Make a few phone calls, or turn off power in a couple of central facilities, and you’ve (legally) disconnected the domestic Internet from the global Internet. Of course, this level of centralization also makes it much harder for the government to defend the nation’s Internet infrastructure against a determined opponent, who knows they can do a lot of damage by hitting just a few targets.
Starting at 10:26 UTC on Thursday, 29 November (12:26pm in Damascus), Syria’s international Internet connectivity shut down. In the global routing table, all 84 of Syria’s IP address blocks have become unreachable, effectively removing the country from the Internet.
We are investigating the dynamics of the outage and will post updates as they become available.
Renesys continues to analyze the impacts on Internet connectivity from Hurricane Sandy. Here’s another quick view of the impact on the routing table as Sandy came ashore Monday night. Each square represents the fate of a set of networks geolocated within a common tenth-degree square of the Earth’s surface — at these latitudes, that’s about [...]
Hurricane Irene knocked out power to millions of homes and businesses as it travelled up the US East Coast this weekend. Even as the winds subsided, torrential rains triggered savage flooding throughout Eastern New York state and Vermont, tearing up roads and exposing the telecommunications infrastructure to further risks. The storm’s impacts were clearly visible in the Internet’s global routing table, as tens of thousands of networks were cut off from the rest of the world.
Here are a couple screenshots from our Internet Health Portal, which we provide to the US Computer Emergency Readiness Team (US-CERT). During an emergency like Hurricane Irene, this tool provides the US-CERT with critical information about the availability of Internet services across America. Working from lists of impacted customers in each state and county, and lists of correlated outage events, we can supply a lot of useful information about the problems being experienced by enterprises in the affected area. That information can be passed along to state and local governments to aid in prioritization of disaster relief.
As dawn broke in Libya on the morning of Sunday 21 August, it appeared that the battle for control of Tripoli was underway. Throughout the night, a steady stream of tweets and retweets emerged from Libyan sources, painting a confusing, often contradictory picture of the evolving situation.
We’re still piecing together the data that can confirm or deny much of what’s been reported overnight, but one thing is clear: something very strange was going on with Tripoli residents’ Internet access. Service was restored suddenly in Tripoli, flickered on and off for a couple of hours, and then died, with the majority of the country’s international BGP routes withdrawn from service for good measure. Today the routes are back in Tripoli, but ADSL service isn’t. This morning we’re looking back at this curious overnight episode, and speculate about what might have happened.
There hasn’t been much to say about the Internet in Libya this summer, as their patterns of connectivity have been fairly stable. It was interesting, therefore, to observe that much of the country’s Internet routing has started to show evidence of sporadic failures this week, which have gone unreported in the media. The following plot [...]