2023
https://habr.com/ru/company/southbridge/blog/720192/
2021
https://www.cyberciti.biz/faq/ubuntu-20-04-lts-set-up-openvpn-server-in-5-minutes/
https://habr.com/ru/post/577404/
https://habr.com/ru/post/550206/
2019
https://habr.com/post/435802/