Dyn issues affecting joint customers

On October 21, 2016, a large-scale Denial-of-Service (DoS) attack targeted Dyn DNS, potentially affecting websites using both Cloudflare and Dyn services. The issue arises when CNAME records pointing to a zone hosted on Dyn fail, causing website unavailability and presenting a "1001" error message. Some popular platforms that rely on Dyn include GitHub Pages, Heroku, Shopify, and AWS. A possible workaround is updating Cloudflare DNS records from CNAMEs to A/AAAA records specifying the origin IP of the website. However, this may cause loss of functionality if different origin IP addresses are used based on geographical location. Customers with a CNAME setup where the main zone is hosted on Dyn might also be affected and can consider making Cloudflare their authoritative DNS provider by contacting support. The Cloudflare status page and support system may be impacted due to being hosted on third parties.