Network security starts from authenticating the user, usually with the username and password. Since this requires one thing, besides the user name, or password that is something we “know”, this is sometimes called an authentication factor. With two-factor authentication something you ‘have’ is also used (eg a security token or dongle, an ATM card or your mobile phone), or three factors of authentication rather than “are” also is used (eg a fingerprint or retina scan).

Once authenticated, a firewall enforces access policies such as what services are allowed access to users.Though effective network to prevent unauthorized access, this component may fail to check potentially harmful contents such as computer worms or Trojan horses that are transmitted over the network. Antivirus software or an intrusion prevention system (IPS) to help detect and inhibit the action of malware. An intrusion detection system based on abnormalities may also monitor network traffic and contingency (ie suspected) the content or behavior and other anomalies to protect the resources, for example, denial of service attack or an employee access to the files, sometimes strange. Individual events occurring on the network may be logged for audit purposes and for subsequent high-level analysis.

Communication between two hosts using a network could be encrypted to maintain privacy.

Honeypots, essentially decoy network-accessible resources, could be deployed in a network as surveillance and early warning tools, the honeypot is not usually access. Techniques used by attackers who try to jeopardize these resources lure studied during and after an attack to keep an eye on new techniques of exploitation. This analysis could be used to further tighten the security of the actual network being protected by the honeypot.