The use of a good security policy and the implementation of different protection mechanisms against different attacks have become, for a few years, essential solutions to network security. In this end-of-study project, we studied the case of the GEC'S firm's computer park and we adopted an architecture that meets its needs. A software of management of the park GLPI as well as various servers were installed namely the Web server LMAP, the file servers SAMBA and NFS, the FTP server and the DHCP server. This architecture is secured by the implementation of a firewall, a Proxy server and an SSH server.