What is network security?

Network security is a cybersecurity discipline covering software, hardware, policies, and training designed to prevent unauthorized access to computer networks.

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Network security measures shield devices on a given network from external cyberattacks

Why is network security important?

Network security is important because it’s your first line of defense against attacks from the outside. By implementing effective network security measures, you can prevent malicious actors from mapping your infrastructure, disrupting your communications, carrying out denial-of-service (DoS) attacks, or reaching critical apps and devices.

Beyond its role in cybersecurity, a good network security policy will also improve the network’s performance. Regulating the types of traffic, processes, and applications that are permitted on the network will keep it running smoothly even during the busiest periods.

Network security works like a padlock against unauthorized intruders trying to access the network

How does network security work?

Network security is built upon the information security triad — confidentiality, integrity, and availability (CIA). Put simply, the data should not be seen by unauthorized users, be protected from tampering, and be available to those who have the right to see it.

Because the same person can come in contact with the same network in a different environment and under a different online identity (such as a guest account) effective security solutions must implement measures at all levels of network access.

Physical network security measures stop attacks with physical objects, such as infected USB sticks

Administrative network security measures like office Wi-Fi policies determine network user privileges

Technical network security measures like VPNs prevent criminals from hacking the network

What are the types of network security?

Physical network security
Tools and processes to prevent unauthorized people from physically reaching the network. The most common physical network security measure is requiring an access card to enter the premises.
Administrative network security
Policies and privileges governing what specific users can do on the network, such as prohibiting non-IT staff from making infrastructure changes. Administrative network security also includes training in cybersecurity.
Technical network security
All software and hardware that monitor network processes for signs of intruders, quarantine identified threats, and stop unauthorized traffic from going in or out the network. This category includes virtual private networks, firewalls, and antiviruses.

Physical network security

Tools and processes to prevent unauthorized people from physically reaching the network. The most common physical network security measure is requiring an access card to enter the premises.

Administrative network security

Policies and privileges governing what specific users can do on the network, such as prohibiting non-IT staff from making infrastructure changes. Administrative network security also includes training in cybersecurity.

Technical network security

All software and hardware that monitor network processes for signs of intruders, quarantine identified threats, and stop unauthorized traffic from going in or out the network. This category includes virtual private networks, firewalls, and antiviruses.

What are effective network security measures?

Network access control

Network access control (NAC) manages user access rights, keeps devices without required cybersecurity out of the network, and disseminates configuration files to the organization’s devices.

VPNs

A virtual private network (VPN) routes the user’s internet traffic through a secure server, giving them safe access to internal resources and preventing others from intercepting sensitive data.

Anti-malware

Antiviruses and other malware protection apps help prevent a contagion from spreading across the network. Anti-malware applications identify infections, alert security, and quarantine files until a solution is found.

Multi-factor
authentication

Multi-factor authentication (MFA) requires users to perform additional steps to prove their identity to the network. MFA can stop malicious actors from wreaking havoc with a high-level user’s password.

Firewalls

A firewall blocks unauthorized users or devices that try to access the network. Firewalls range from simple packet filters to cutting-edge software with sophisticated AI to analyze data on the fly.

Intrusion detection systems

An intrusion detection system (IDS) constantly monitors network activity for irregular behavior. IDS is often combined with intrusion prevention systems (IPS) to automatically respond to breaches.

Data loss prevention

Instead of keeping intruders out, data loss prevention (DLP) measures prevent sensitive information from leaving the network. For example, DLP may require encrypting files stored in the cloud.

Secure web gateways

Secure web gateways combine aspects of firewalls, URL filtering tools, and application control measures to prevent hackers from accessing the network or insiders visiting dangerous sites.

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Frequently asked questions

Who is responsible for network security?

In most organizations, cybersecurity (and, by extension, network security) policies are managed either by a chief information officer (CIO), chief information security officer (CISO), or an IT manager. Day-to-day network security is overseen by cybersecurity technicians, who typically belong to the organization’s IT department.

What is the difference between network and cyber security?

Network security is a branch of cybersecurity that deals with protecting networks from intrusion and data theft. It uses many of the same tools, but network security policies focus on the bigger picture. For example, in network security, an antivirus helps isolate incidents and prevent infections from spreading to connected devices.

What is a network security threat?

A network security threat is any malicious action or software intended to infiltrate or disrupt a network. Once the network is compromised, these actors can monitor data traffic or spy on individual devices. Common network security threats include denial-of-service (DoS) attacks, social engineering attempts, and malware in messages.