DNS flag day
On 1 February 2019, major Domain name system (DNS) providers such as CISCO, CZ.NIC, Google, Cloudflare, and Facebook, released new software updates that will stop supporting the old workarounds that existed for the DNS resolution process and allowed users to bypass the Extension Mechanisms Protocol for DNS (EDNS). EDNS is a set of extension mechanisms to expand the size of the DNS message as it goes through its query, which allows more information to be included in the communication between each host in the DNS resolution process. Because of the efforts to accommodate a few DNS systems, including EDNS, that are not in compliance with DNS standards established two decades ago, the providers have decided to stop supporting old workarounds.