Linux Hardening in Hostile Networks: Server Security from TLS to Tor

4. Network

Along with workstation and server hardening, network hardening is a fundamental part of infrastructure security. In the past, network hardening has been primarily focused on perimeter security with the use of firewalls at the edge of the network to block incoming traffic that isn’t authorized. Later, the focus extended to blocking outgoing traffic in those firewalls as well, primarily to prevent employees from unauthorized web browsing but also to prevent proprietary data from leaking out of the network. These days it’s generally recognized that the inside of the network is as much of a threat as the outside. A firewall at the edge of your network doesn’t do much good if an internal workstation or server is hacked and used as a jumping ...