There are three basic ways of hardening.
1. Operating system hardening: Here the operating system is hardened (making tough to intrude). Few points that would help in hardening an operating system:
2. Network hardening: This involve the following
3. Application Hardening: Applications such as DNS servers, Web server, Mail servers, File and print servers can be hardened by the following means:
All Microsoft Windows operating systems Windows 95 and above contain built in support for File and Printer Sharing. This networking feature is useful on home networks but can be a security concern on public networks. It is preferred to disable this feature if connected to the Internet.
Disabling Unused ports: Disable Unused Ports. A simple method that many administrators use to help secure the network from unauthorized access is to disable all unused ports on a switch. For example, if a Catalyst 2960 switch has 24 ports and there are three Fast Ethernet connections in use, it is good practice to disable the 21 unused ports.