What is network security?

Network security can protect your IT infrastructure from various threats.

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Network security defined

At a foundational level, network security is the operation of protecting data, applications, devices, and systems that are connected to the network.

Though network security and cybersecurity overlap in many ways, network security is most often defined as a subset of cybersecurity. Using a traditional “castle-and-moat analogy,” or a perimeter-based security approach – in which your organization is your castle, and the data stored within the castle is your crown jewels – network security is most concerned with the security within the castle walls.

In this perimeter-based scenario, the area within the castle walls can represent the IT infrastructure of an enterprise, including its networking components, hardware, operating systems, software, and data storage. Network security protects these systems from malware/ransomware, distributed denial-of-service (DDoS) attacks, network intrusions, and more, creating a secure platform for users, computers, and programs to perform their functions within the IT environment.

As organizations move to hybrid and multicloud environments, their data, applications, and devices are being dispersed across locations and geographies. Users want access to enterprise systems and data from anywhere and from any device. Therefore, the traditional perimeter-based approach to network security is phasing out. A zero-trust approach to security, wherein an organization never trusts and always verifies access, is fast becoming the new method for strengthening an organization’s security posture.


Types of Network Security

Firewall protection

A firewall is either a software program or a hardware device that prevents unauthorized users from accessing your network, stopping suspicious traffic from entering while allowing legitimate traffic to flow through. There are several types of firewalls with different levels of security, ranging from simple packet-filtering firewalls to proxy servers to complex, next-generation firewalls that use AI and machine learning to compare and analyze information as it tries to come through.

Intrusion detection and prevention

Intrusion detection and prevention systems (IDPS) can be deployed directly behind a firewall to provide a second layer of defense against dangerous actors. Usually working in tandem with its predecessor, the more passive intrusion defense system (IDS), an IDPS stands between the source address and its destination, creating an extra stop for traffic before it can enter a network. An advanced IDPS can even use machine learning and AI to instantly analyze incoming data and trigger an automated process – such as sounding an alarm, blocking traffic from the source, or resetting the connection – if it detects suspicious activity.

Network access control (NAC)

Standing at the frontline of defense, network access control does just that: it controls access to your network. Most often used for “endpoint health checks,” NAC can screen an endpoint device, like a laptop or smart phone, to ensure it has adequate anti-virus protection, an appropriate system-update level, and the correct configuration before it can enter. NAC can also be programmed for “role-based access,” in which the user’s access is restricted based on their profile so that, once inside the network, they can only access approved files or data.

Cloud security

Cloud security protects online resources – such as sensitive data, applications, virtualized IPs, and services – from leakage, loss, or theft. Keeping cloud-based systems secure requires sound security policies as well as the layering of such security methods as firewall architecture, access controls, Virtual Private Networks (VPNs), data encryption or masking, threat-intelligence software, and disaster recovery programs.

Virtual Private Networks (VPNs)

A virtual private network (VPN) is software that protects a user’s identity by encrypting their data and masking their IP address and location. When someone is using a VPN, they are no longer connecting directly to the internet but to a secure server which then connects to the internet on their behalf. VPNs are routinely used in businesses and are increasingly necessary for individuals, especially those who use public wifi in coffeeshops or airports. VPNs can protect users from hackers, who could steal anything from emails and photos to credit card numbers to a user’s identity.

Data loss prevention (DLP)

Data loss prevention (sometimes called “data leak prevention”) is a set of strategies and tools implemented to ensure that endpoint users don’t accidentally or maliciously share sensitive information outside of a corporate network. Often put in place to comply with government regulations around critical data (such as credit card, financial or health information), DLP policies and software monitor and control endpoint activities on corporate networks and in the cloud, using alerts, encryption, and other actions to protect data in motion, in use, and at rest.

Endpoint protection

Often requiring a multi-layered approach, endpoint security involves protecting all of the endpoints – laptops, tablets, smartphones, wearables, and other mobile devices – that connect to your network. Although securing endpoints is a complex endeavor, a managed security service can help keep your devices, data, and network safe using antivirus software, data loss prevention, encryption, and other effective security measures.

Unified threat management (UTM)

With UTM appliances, organizations can reduce costs and improve the manageability of network protection and monitoring using multiple network-security tools such as firewalls, VPNs, IDS, web-content filtering, and anti-spam software.

Secure web gateway

This security technology prevents unauthorized network traffic from entering the internal network and protects users and employees that may access malicious websites that contain viruses or malware. Secure web gateways typically include web-filtering technology and security controls for web applications.


How does network security work?

At its most fundamental level, secure networking centers on two basic tenets: authentication and authorization. In other words, first you need to make sure that every user in your network is an authentic user that is permitted to be there, and then you need to make sure that each user within your network is authorized to access the specific data that they are accessing.

Network security basics

Network security involves everything from setting and enforcing enterprise-wide policies and procedures, to installing software and hardware that can automatically detect and block network security threats, to hiring network security consultants and staff to assess the level of network protection you need and then implement the security solutions required.

Managed security services (MSS)

Managed security services can help secure today’s increasingly complex hybrid multicloud networks. Advanced managed security services even offer around-the-clock monitoring, management, and response to advanced threats, risks, and compliance requirements.


Related solutions

Network penetration testing

If attackers exploit just one vulnerability in your network, they could potentially compromise the entire environment. But with so many possible access points, where do you start testing your system? X-Force Red, IBM Security’s team of veteran hackers, can help prioritize which components to test, and then identify and help fix the highest-risk vulnerabilities within an organization’s internal and external networks.

Incident response solutions

Nearly three-quarters of organizations don’t have a consistent, company-wide cybersecurity incident response plan. Yet having a plan in place could save millions of dollars in the event of a data breach. IBM Security resources can help your organization prepare for, detect, and respond to whatever incidents come your way.

Security information and event management (SIEM)

SIEM solutions have evolved to include advanced user behavior analytics (UBA), network flow insights, and artificial intelligence to enhance threat detection and integrate seamlessly with security, orchestration, automation, and response (SOAR) platforms. Build your SIEM foundation with the help of skilled consultants who can help.

IT infrastructure security

Case studies testify to the strength of IBM’s scalable security solutions for IT infrastructures. Learn how Carhartt, the Met Office, and Bradesco, one of Brazil’s largest banks, have applied IBM technology and management offerings to keep their data secure, whether on premises, in the cloud, or moving in between.

Cloud infrastructure for network security

Firewalls and security groups are important in securing your cloud environment and the information stored in it, as well as preventing malicious activity from reaching your servers or users.

Cybersecurity solutions

Align your security strategy with your business, protect your digital assets, manage your defenses against growing threats, and modernize your security strategies with IBM Security Services. Explore strategies for identity and access management, SIEM and SOAR, multicloud security, and more.