On Friday, Cloudflare suffered a 27-minute outage that impacted websites such as Politico, GitLab, Zendesk, and Discord. Cloudflare subsequently blamed the outage on its 18.104.22.168 DNS service on a configuration error on one of its routers in Atlanta.
"We had an issue that impacted some portions of the Cloudflare network," Cloudflare CEO Matthew Prices wrote on Twitter on Friday. "It appears that a router in Atlanta had an error that caused bad routes across our backbone. That resulted in misrouted traffic to PoPs that connect to our backbone."
In a company blog, Cloudflare said it saw traffic drop by about 50% across its network.
"The outage occurred because, while working on an unrelated issue with a segment of the backbone from Newark to Chicago, our network engineering team updated the configuration on a router in Atlanta to alleviate congestion," said Cloulflare's John Graham-Cumming, in his Friday blog post. "This configuration contained an error that caused all traffic across our backbone to be sent to Atlanta. This quickly overwhelmed the Atlanta router and caused Cloudflare network locations connected to the backbone to fail."
Graham-Cumming said the affected locations were San Jose, Dallas, Seattle, Los Angeles, Chicago, Washington, DC, Richmond, Newark, Atlanta, London, Amsterdam, Frankfurt, Paris, Stockholm, Moscow, St. Petersburg, São Paulo, Curitiba, and Porto Alegre. Other locations continued to operate normally. He also stressed that the outage wasn't caused by an attack or breach of any kind.
In addition to the blog explaining how the outage happened, Cloudflare provided updates during and after the outage. San Francisco-based Cloudflare said on Friday it was looking at issues with its Cloudflare Resolver and edge network in certain locations. In addition to web sites being down, some status pages weren't working as well.
"A significant portion of Cloudflare’s DNS services went down for ~20 min causing major service disruptions. The services include its public resolver plus its managed DNS service, which powers many major websites," according to a spokesperson for network-monitoring vendor ThousandEyes, in an email Saturday to FierceTelecom. "It also impacted DNS Roots E & F, both supported by Cloudflare."