Understanding how Facebook disappeared from the Internet
October 04, 2021 9:08 PM
Today at 1651 UTC, we opened an internal incident entitled "Facebook DNS lookup returning SERVFAIL" because we were worried that something was wrong with our DNS resolver 1.1.1.1. But as we were about to post on our public status page we realized something else more serious was going on....
A Byzantine failure in the real world
November 27, 2020 12:00 PM
At Cloudflare, we are always on the lookout for Single Points of Failure. In this post, we explore the role a failure mode known as a Byzantine fault played in a a real-world incident....
August 30th 2020: Analysis of CenturyLink/Level(3) outage
August 30, 2020 8:55 PM
Today CenturyLink/Level(3), a major ISP and Internet bandwidth provider, experienced a significant outage that impacted some of Cloudflare’s customers as well as a significant number of other services and providers across the Internet. ...
Cloudflare outage on July 17, 2020
July 18, 2020 1:22 AM
Today a configuration error in our backbone network caused an outage for Internet properties and Cloudflare services that lasted 27 minutes. We saw traffic drop by about 50% across our network....
MORE POSTS
July 12, 2019 3:45 PM
Details of the Cloudflare outage on July 2, 2019
Almost nine years ago, Cloudflare was a tiny company and I was a customer not an employee. Cloudflare had launched a month earlier and one day alerting told me that my little site, jgc.org, didn’t seem to have working DNS any more. ...
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July 02, 2019 3:50 PM
Cloudflare outage caused by bad software deploy (updated)
Starting at 1342 UTC today we experienced a global outage across our network that resulted in visitors to Cloudflare-proxied domains being shown 502 errors (“Bad Gateway”). The cause of this outage was deployment of a single misconfigured rule within the Cloudflare Web Applicatio...
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November 15, 2018 5:22 PM
How a Nigerian ISP Accidentally Knocked Google Offline
Last Monday evening — 12 November 2018 — Google and a number of other services experienced a 74 minute outage. Incidents like this only serve to demonstrate just how much frailty is involved in how packets get from one point on the Internet to another....
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September 07, 2017 8:58 PM
The Story of Two Outages
Over the last two days, Cloudflare observed two events that had effects on global Internet traffic levels. Cloudflare handles approximately 10% of all Internet requests, so we have significant visibility into traffic from countries and networks across the world....
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August 16, 2017 12:15 AM
Power outage hits the island of Taiwan. Here’s what we learned.
At approximately 4:50pm local time (8:50am UTC) August 15, a major unexpected power outage hit the island of Taiwan with a significant amount of its power generation facilities going down....
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November 30, 2016 1:00 AM
Not one, not two, but three undersea cables cut in Jersey
Sometime before midnight Monday (UK local time) a ship dropped its anchor and broke, not one, not two, but three undersea cables serving the island of Jersey in the English Channel. ...
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October 27, 2016 12:10 PM
How the Dyn outage affected Cloudflare
Last Friday the popular DNS service Dyn suffered three waves of DDoS attacks that affected users first on the East Coast of the US, and later users worldwide. ...
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October 21, 2016 6:22 PM
Dyn issues affecting joint customers
Today there is an ongoing, large scale Denial-of-Service attack directed against Dyn DNS. While Cloudflare services are operating normally, if you are using both Cloudflare and Dyn services, your website may be affected....
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May 08, 2013 11:10 AM
Syrian Internet Restored
Yesterday, Syria's Internet connectivity was cut off from the rest of the world. At 14:12 UTC, approximately 19 hours and 30 minutes after it had been shut down, connectivity was returned....
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May 07, 2013 2:13 PM
How Syria Turned Off the Internet (Again)
Today at 18:48 UTC, Syria dropped off the Internet. Based on the data we collect from our network, as well as reports from other organizations monitoring network routes, it appears that someone systematically withdrew the BGP. ...
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March 03, 2013 1:47 PM
Today's Outage Post Mortem
This morning at 09:47 UTC CloudFlare effectively dropped off the Internet. The outage affected all of CloudFlare's services including DNS and any services that rely on our web proxy....
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December 01, 2012 3:35 PM
Syrian Internet access reestablished starting 1432 UTC
Syria has reestablished partial connectivity to the Internet. The following map of BGP connectivity shows Syria's 29386 network connected to multiple networks outside Syria....
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November 29, 2012 8:13 PM
How Syria Turned Off the Internet
Today, 29 November 2012, between 1026 and 1028 (UTC), all traffic from Syria to the rest of the Internet stopped. At CloudFlare, we witnessed the drop off. We've spent the morning studying the situation to understand what happened. ...
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November 06, 2012 9:09 AM
Why Google Went Offline Today and a Bit about How the Internet Works
Today, Google's services experienced a limited outage for about 27 minutes over some portions of the Internet. The reason this happened dives into the deep, dark corners of networking. ...
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