ALTAI, Sadeer Sadeq Abduljabbar; WID BADEE ABDULAZIZ; ALSAADI, Rafid najim abdullah; MABROUKA M.A. ALGHERINI. Enhancing Server Security: Implementation and Evaluation of the Port Knocking Method on Ubuntu Virtual Servers. Journal of Engineering and Sustainable Development, Baghdad, Iraq, v. 29, n. 6, p. 752–763, 2025. DOI: 10.31272/jeasd.2809. Disponível em: https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/2809.. Acesso em: 17 jun. 2026.