Short description: Loss of internet functionality over a small or large area
Electronic information stand without an internet connection, at Schiphol Airport, Netherlands
An Internet outage or Internet blackout or Internet shutdown is the complete or partial failure of the internet services. It can occur due to censorship, cyberattacks, disasters,[1] police or security services actions[2] or errors.
Disruptions of submarine communications cables may cause blackouts or slowdowns to large areas. Countries with a less developed Internet infrastructure are more vulnerable due to small numbers of high-capacity links.
A line of research finds that the Internet with it having a "hub-like" core structure that makes it robust to random losses of nodes but also fragile to targeted attacks on key components − the highly connected nodes or "hubs".[3]
A government internet blackout is the deliberate shut down of civilian internet access by a government for a small area or many large areas of its country. Such a shut down is typically used as a means of information control in a brief period of upheaval or transition. In autocracies, internet shutdowns have appeared especially in the context of contested elections and post-electoral violence.[4] It can impede the ability of protesters or insurgent forces to mobilize and organize. It also serves to prevent real-time information access for foreign people or entities. Reactions from leaders, journalists, observers and others in foreign countries can be delayed.
Military blackout
The temporary disconnection of civilian internet access by military forces is an important aspect of information warfare. This tactic is common today, and is often used in concert with a ground invasion by conventional forces. It could also be used in advance of an airstrike campaign.
Weather or natural disaster
Extreme weather events and natural disasters can lead to internet outages by either directly destroying local ICT infrastructure or indirectly damaging the local electricity grid. The Monash IP Observatory and KASPR Datahaus have tracked the impact of Hurricane Florence 2018,[5] Cyclone Fani 2018,[6] and Hurricane Laura in 2020.[7]
Solar storms
Solar superstorms could cause large-scale global months-long Internet outages. Researchers have described potential mitigation measures and exceptions – such as user-powered mesh networks, related peer-to-peer applications and new protocols – and the robustness of the current Internet infrastructure.[8][9][10]
Cyberattacks
Distributed Denial of Service (DDoS) attacks
Screenshot of the Wikipedia website during a DDoS attack in February 2020, showing an error message in place of website content
These attacks flood a website or network with traffic from multiple sources, overwhelming the server and making it unavailable to users.
Routing attacks
These attacks target the infrastructure of the internet, specifically the routing systems that direct traffic between different networks. By manipulating or disrupting these systems, attackers can cause widespread outages.
Malware
Malicious software can infect and damage computer systems and networks, leading to internet outages.
Botnets
A botnet is a network of compromised computers that are controlled by an attacker. These computers can be used to launch DDoS attacks, spread malware, or perform other malicious actions that can cause internet outages.
Border Gateway Protocol (BGP) Hijacking
Border Gateway Protocol (BGP) is used to route traffic on the internet. BGP hijacking is a form of cyber-attack where an attacker alters the routing information in BGP, causing internet traffic to be directed to the wrong place.
Accidents
Natural disasters
Floods, hurricanes, earthquakes, and other natural disasters can damage internet infrastructure, causing outages.
Power failures
Internet service providers (ISPs) rely on electricity to power their networks, so power failures can cause outages.
Human error
Accidents caused by human error, such as a construction crew cutting through a fiber-optic cable, can cause internet outages.
Equipment failure
The failure of equipment such as servers, routers, and switches can cause internet outages.
Maintenance
Scheduled maintenance or unexpected repairs on the internet infrastructure can cause outages.
Weather condition
Inclement weather such as heavy snow, thunderstorm, and heavy rain can cause outages by damaging the infrastructure or making it difficult for maintenance crews to access and repair the network.
Measurement
A variety of organizations measure internet shutdowns including the Open Observatory of Network Interference, Access Now, Freedom House, the Digital Society Project (using the V-Dem Institute methodology and infrastructure), the OpenNet Initiative, the University of Michigan's Censored Planet Observatory, the Internet Censorship Lab, and the Monash IP Observatory.[11][12][13][14][15][16][17] These organizations use a range of methods to detect shutdowns such as expert analysis, remote sensing, and remote sensing with oversight.[16] Some of these organizations, such as Access Now, maintain active lists of internet shutdowns.[18]
Expert Analysis
Several organizations use expert analysis to identify internet shutdowns.[16] Some, such as the Digital Society Project (DSP), send out surveys to experts around the world, and then aggregate the results into a single score. For internet shutdowns, the DSP asks "How often does the government shut down domestic access to the Internet?" where answers range from "Extremely Often" to "Never or almost Never."[19] Freedom House's Freedom on the Net report also uses expert analysis to assess whether internet shutdowns have occurred, but instead of surveying multiple experts, Freedom House identifies and partners with a single expert to conduct an analysis.[12] Freedom House asks the question "Does the government intentionally disrupt the internet or cellphone networks in response to political or social events, whether temporary or long term, localized or nationwide?"[12] Generally expert analyses are more prone to false positives and fewer false negatives (i.e. identifying shutdowns that other sources cannot confirm), than remote sensing methods with manual oversight.[16]
Remote Sensing
Other organizations use various remote sensing techniques to identify shutdowns.[16] Some organizations, such as the Open Observatory of Network Interference, the Internet Censorship Lab and the Monash IP-Observatory use automated remote sensing methods to detect internet shutdowns.[11][20][21] The Open Observatory of Network Interference uses software installed on computers of volunteers around the world to detect shutdowns. However these methods are prone to false positives, false negatives, and various technical challenges.[22][23][24]
In order to address these concerns, some organizations have implemented various methods of oversight.[16] Organizations such as Access Now and the OpenNet Initiative use such methods.[15] Access Now uses technological methods to detect shutdowns, but then confirms those shutdowns using news reports, reports from local activists, official government statements, and statements from ISPs.[15] The OpenNet Initiative has volunteers install software on their computers to check websites from access points around the world, then confirms those results with manual observations.[25] These methods are prone to more false negatives and fewer false positives (i.e. all shutdowns that these sources identify can be confirmed by other sources) than expert analyses.[16]
A comparatively new method for detecting internet shutdowns is remote sensing with automated oversight. These methods have been praised as more ethical and efficient as they do not endanger in-country volunteers.[26][27][28][23] However these methods have yet to produce regular datasets.[16]
List
Year
Name
Country or region
Affected users
Number of affected users (rough)
Description
Duration (rough)
Internet component
Cause
Entity responsible
Type
16 Jul 1997
DNS TLD Outage
Worldwide
50,000,000
An Ingres database failure resulted in corrupt .com and .net zones, which were subsequently released to the DNS root servers. As the root servers were reloaded, they began to return failures for all domains in the .com and .net zones.[29][30]
Three separate incidents of major damage to submarine optical communication cables around the world occurred in 2008. The first incident caused damage involving up to five high-speed Internetsubmarine communications cables in the Mediterranean Sea and Middle East from 23 January to 4 February 2008, causing internet disruptions and slowdowns for users in the Middle East and India .[31] In late February there was another outage, this time affecting a fiber optic connection between Singapore and Jakarta.[32] On 19 December, FLAG FEA, GO-1, SEA-ME-WE 3, and SEA-ME-WE 4 were all cut.[33][34][35]
submarine cables
Unknown
Unknown
2009
Death of Michael Jackson
United States
Shortly after the death of pop singer Michael Jackson, thousands of online media posts and users rapidly attempted results of Michael Jackson on how he died. This resulted in Google blocking Michael Jackson-related searches (after assumption that a DDoS attack was at hand), Twitter and Wikipedia crashed, and AOL Instant Messenger collapsing for 40 minutes.
Two incidents of submarine communications cables cut off on 25 December 2011. The first cut off occurred to SEA-ME-WE 3 at Suez canal, Egypt and the second cut off occurred to i2i which took place between Chennai, India and Singapore line. Both the incidents had caused the internet disruptions and slowdowns for users in the South Asia and Middle East in particular UAE.[36][37][38][39]
submarine cables
Unknown
Unknown
2011
Armenia
3,000,000
A woman digging for scrap metal damaged land cables and thereby severed most connectivity for the nation of Armenia.[40]
5 hours
land cables
digging
Unknown
Full
2011
Egypt
The Internet in Egypt was shut down by the government, whereby approximately 93%[41] of networks were without access in 2011 in an attempt to stop mobilization for anti-government protests.[42]
ISPs
government censorship
Egypt
Full
2012
2012 Syrian internet outage
Syria
On 29 November 2012 the Syrian internet was cut off from the rest of the world. The autonomous system (AS29386) of Syrian Telecommunication Establishment (STE) was cut off completely at 10:26 UTC. Five prefixes were reported to have remained up, this is why Dyn[43] reports an outage of 92% of the country.
Responsibility for the outage has somewhat speculatively been blamed on various organizations.[44][45]
Unknown
Unknown
2016
Germany
Deutsche Telekom
900,000
At the end of November 2016 0.9 million routers, from Deutsche Telekom and produced by Arcadyan, were crashed due to failed TR-064 exploitation attempts by a variant of Mirai, which resulted in internet connectivity problems for the users of these devices.[46][47] While TalkTalk later patched their routers, a new variant of Mirai was discovered in TalkTalk routers.[48][49][50]
1 day
Internet routers
cyberattack
Unknown
Full
2016
Liberia
Mirai has also been used in an attack on Liberia's internet infrastructure in November 2016.[51][52][53]
The cyberattack took place on October 21, 2016, and involved multiple distributed denial-of-service attacks (DDoS attacks) targeting systems operated by Domain Name System (DNS) provider Dyn, which caused major internet platforms and services to be unavailable to large swathes of users in Europe and North America.[54][55] As a DNS provider, Dyn provides to end-users the service of mapping an Internet domain name—when, for instance, entered into a web browser—to its corresponding IP address. The distributed denial-of-service (DDoS) attack was accomplished through a large number of DNS lookup requests from tens of millions of IP addresses.[56] The activities are believed to have been executed through a botnet consisting of a large number of Internet-connected devices—such as printers, IP cameras, residential gateways and baby monitors—that had been infected with the Mirai malware. With an estimated throughput of 1.2 terabits per second, the attack is, according to experts, the largest DDoS attack on record.[57]
On January 17, around 20 percent of the people in Cameroon had their internet blocked due to recent anti-government protests.[58][59][60]
270 days or 8 months
government censorship
Cameroon
Full
2017
North Korea
On October 1, The autonomous system (AS131279) of Star JV was cut off completely, due to alleged US cyber attack[61][62][63]
9 hours and 31 minutes
cyberattack
United States
Full
2019
Verizon and BGP Optimizer
United States
Verizon (company)
On June 24, 2019, many parts of the Internet faced an unprecedented outage as Verizon, the popular internet transit provider accidentally rerouted IP packages after it wrongly accepted a network misconfiguration from a small ISP in Pennsylvania, US.[64] According to The Register, systems around the planet were automatically updated, and connections destined for Facebook, Cloudflare, and others, ended up going through DQE and Allegheny, which buckled under the strain, causing traffic to disappear into a black hole.[65]
3 hours
Internet transit provider
misconfiguration
Unknown
Major websites
2019
Iranian internet shutdown
Iran
The Internet in Iran was shut down by the government, whereby approximately 96% of networks were without access in an attempt to stop mobilization for anti-government protests.
7 days
ISPs
government censorship
Iran
Full
2019
Internet shutdown in India
India
50,000,000
The Government of India passed the Citizenship Amendment Act, 2019 which caused huge controversy and mass protest in various parts of India . In order to prevent protests and outrage on social media, various state governments including those of Assam, Tripura, Meghalaya, Arunachal Pradesh, West Bengal, Uttar Pradesh decided to shut down internet access.
To curb the escalating protests occurred in the Indonesian provinces of Papua and West Papua, Indonesian authority imposed an internet blackout on both provinces on 21 August 2019. The blackout continues until the authority partially lift the blackout in 4 September on several regions, with complete lifting of the restriction only occurred in 9 September.[68]
19 days
government censorship
Indonesia
Full
2021
North Korea
On October 21st, North Korean internet infrastructure dropped off the internet, including public facing websites and email servers. All servers which were subject to monitoring were found to be offline.[69]
At least 14 minutes
Unknown
Unknown
2021
Facebook outage
Worldwide
LAN Internet Connection
2,850,000,000
On October 4, 2021, at around 11:45 AM EST, the online social media site Facebook went down, as well as Facebook subsidiaries including Instagram and WhatsApp. Around 4:00 PM EST, people reported other sites were not working via Downdetector, including Gmail and Twitter, the latter possibly caused by Facebook users reporting the outage.[70][71][72] The outage came less than a day after a whistleblower had been on 60 Minutes.[73] For a short period of time, no Facebook employee could access the building to investigate the issue due to their "keycards not working.".[74] At around 6:30 PM EST, Facebook reported that all their sites were up. Facebook CEO Mark Zuckerberg lost around $7B dollars after the outage.[75]
For more info, see 2021 Facebook outage
7 hours
LAN connection
BGP Withdrawal of IP Address (Facebook), Server overwhelming (other sites)
Unknown
Major websites
2022
2022 Kazakhstan internet shutdown
Kazakhstan
On 4 January 2022 the Internet in Kazakhstan was shut down on account of anti-government protests against sudden energy price rises.[76]
5 days
government censorship
Kazakhstan
mobile internet
2022
Rogers outage
Canada
On July 8th, 2022, Rogers reported the largest outage in Canadian history. The outage affected both cable Internet and cellular networks, as well as critical infrastructure that used them, including Interac debit payments, hospitals, banks, and 9-1-1 access. The outage occurred during an update to the company's core IP network that resulted in the deletion of a routing filter on its distribution routers, which caused all possible routes to the internet to pass through the routers, exceeding the capacity of the routers on its core network.
1 day
Network Update
Internal
Full
2022
2021–2023 Iranian protests
Iran
80 million
globally cutting off its people’s access to the internet ,whilst maintaining domestic national internet National Information Network [77][78][79]
Prevention
Internet outages can be prevented by a more resilient, decentralized Internet architecture.[80]
Management
Modern society, especially in developed countries, depends heavily on the Internet not just for communication. There have been some measures taken and possibilities exist for managing and countering a large-scale Internet outage.[citation needed]
↑Petersen, Hauke; Baccelli, Emmanuel; Wählisch, Matthias; Schmidt, Thomas C.; Schiller, Jochen (27 October 2014). "The Role of the Internet of Things in Network Resilience" (in en). Internet of Things. IoT Infrastructures. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering. 151. Springer, Cham. pp. 283–296. doi:10.1007/978-3-319-19743-2_39. ISBN978-3-319-19742-5. Bibcode: 2014arXiv1406.6614P.
↑Jyothi, Sangeetha Abdu (9 August 2021). "Solar superstorms: Planning for an internet apocalypse". Proceedings of the 2021 ACM SIGCOMM 2021 Conference. Association for Computing Machinery. pp. 692–704. doi:10.1145/3452296.3472916. ISBN9781450383837.
↑ 11.011.1Niaki, Arian Akhavan; Cho, Shinyoung; Weinberg, Zachary; Hoang, Nguyen Phong; Razaghpanah, Abbas; Christin, Nicolas; Gill, Phillipa (2019-07-09). "ICLab: A Global, Longitudinal Internet Censorship Measurement Platform". arXiv:1907.04245 [cs.CR].
↑Mechkova, V., Daniel P., Brigitte S.,&Steven W. (2020). Digital Society Project Dataset v2.Varieties of Democracy (V-Dem) Project http://digitalsocietyproject.org/
↑Faris, R. & Villeneuve, N. (2008). Measuring Global Internet Filtering in R. Deibert, J. Palfrey, R. Rohozinski, & J. Zittrain, (Eds.), Access Denied: The Practice and Policy of Global Internet Filtering, Cambridge: MIT Press. http://opennet.net/sites/opennet.net/files/Deibert_02_Ch01_005-028.pdf
↑VanderSloot, B., McDonald, A., Scott, W., Halderman, J.A., & Ensafi, R. (2018). Quack: Scalable Remote Measurement of Application-Layer Censorship. In Proceedings of the 27th USENIX Security Symposium.
↑Hoang, P. N., Doreen, S., Polychronakis, M., (2019). Measuring I2P Censorship at a Global Scale. In Proceedings of the 9th USENIX Workshop on Free and Open Communications on the Internet.
↑Raman, R. S., Stoll, A., Dalek, J., Ramesh, R. Scott, W., & Ensafi, R. (2020). Measuring the Deployment of Network Censorship Filters at Global Scale. Network and Distributed System Security (NDSS) Symposium 2020.