Debian 9 (Stretch) repositories have been moved to archive.debian.org, after which the distribution will soon no longer be available through the main mirror network. The removal of Debian 9 from the main archive is scheduled for April 23.
The release of Debian 9 was announced on June 18, 2017, and was officially supported until July 18, 2020, and in the LTS branch until June 30, 2022. As part of the Extended LTS program, updates addressing vulnerabilities for a limited set of Debian 9 packages for amd64, armel, and i386 architectures will be published in a separate repository until June 30, 2027.
Source: opennet.ru
