Definition

Network security is a collective term that refers to the  hardware, software and procedural methods used to protect a computer network  infrastructure and the systems on it. Computer networks can be vulnerable to  many threats, including unauthorized access, which can lead to confidentiality  breaches, disruption of business operations due to loss of network  availability, and data tampering or destruction.

Business applications

Network security is a complex effort that involves many  technologies to provide defense-in-depth. Experts suggest approaching network  security by first identifying everything that is on the network. Once you know what needs to  be protected, you can determine how to protect it based on your company’s risk  profile.

Best practices dictate that network security should include some standard technologies and procedures:

• Antivirus to prevent malicious code from infecting network systems.
• Firewalls to inspect incoming and outgoing network traffic.
• Strong passwords changed periodically to authenticate users.
• Routers and switches configured appropriately.
• Operating systems kept up to date with patches.
• Security-awareness training for users, including physical security.
• A network analyzer or monitoring device to inspect traffic.

Other countermeasures include content filtering, encryption, virtual private networks, anti-spyware, intrusion-detection and –prevention systems, network access control and unified threat management.

Deployment concerns

The biggest threat to network security also happens to be one that is often overlooked  – the user. Businesses need to be mindful of the possibility of internal  breaches. In unauthorized access, it doesn’t matter whether the intruder is on  the company payroll. Keep access control lists current and use appropriate authentication methods.

The value of a network inventory cannot be overstated. Businesses  cannot protect what they don’t know exists. Make network inventories a regular  practice.

As in e-mail security, dropping a single piece of technology  on the network is not going to provide complete protection. A traditional  network firewall is a vital piece of network security, but it doesn’t stop  there. Businesses should take a layered approach to network security, building  security countermeasures throughout the network for defense-in-depth.

Technical details

Firewall manufacturers are increasingly integrating network  security technologies in what are referred to as unified threat management.  Unified threat management offers the benefit of multiple technologies under one  hood – or dashboard, as the case may be. This is meant to simplify the  installation and management of various technologies while providing protection  against a variety of threats. Unified threat management products usually include antivirus, network firewall, content filtering and anti-spam. Advanced features include intrusion detection/prevention, virtual private network and Web application scanning.