Businesses depend on their networks for nearly everything from accessing files and applications to communicating with customers, processing transactions, and connecting employees working remotely.
That also makes the network an important target for cyber threats.
Protecting a business network isn’t as simple as installing a firewall or antivirus software. Modern network security uses multiple technologies, policies, and security controls that work together to protect users, devices, systems, and data.
So, what are the different types of network security, and what does each one actually do?
What is Network Security
Network security refers to the technologies, processes, and controls used to protect a company’s network, connected devices, applications, and data from unauthorized access, misuse, disruption, and cyber threats.
Years ago, network security was often heavily focused on creating a secure perimeter around an office network.
Today’s business environments are much more complicated.
Employees may work remotely. Applications may run in the cloud. Employees access company information from laptops and mobile devices. Businesses may operate multiple locations, and third-party vendors may need access to certain systems.
As business networks have changed, network security has had to change with them.
Rather than relying on one defensive barrier, businesses can use multiple layers of network security to help prevent, identify, contain, and respond to threats.
What Are the Different Types of Network Security?
There are are many types of network security, and each protects a different part of a business’s technology environment. Some controls focus on preventing unauthorized access, while others help detect suspicious activity, protect connected devices, secure data, or limit how far a threat can spread.
1. Firewalls
A firewall is one of the most recognizable types of network security.
Firewalls monitor and control network traffic based on established security rules. They essentially act as a checkpoint between different networks or network segments, deciding which traffic should be allowed through and which should be blocked.
For example, a firewall can be configured to restrict traffic coming from certain network addresses, applications, or ports while allowing legitimate business traffic.
Modern firewalls may also provide capabilities beyond basic traffic filtering, including application awareness, intrusion prevention, threat detection, and other security functions.
However, having a firewall doesn’t mean a business network is completely protected.
A firewall is one layer of security, not the entire security strategy.
2. Network Monitoring
You can’t protect a network effectively if you don’t know what’s happening on it.
Network monitoring provides visibility into the health, availability, performance, and activity of network infrastructure.
Depending on the tools being used, monitoring may help identify:
- Unusual network traffic
- Devices going offline
- Performance problems
- Connectivity issues
- Network equipment failures
- Unexpected activity
- Resource utilization
- Potential security events
Monitoring can also help IT teams identify problems before employees begin reporting that something isn’t working.
From a security perspective, unusual network activity can sometimes be an early indicator that an account, device, or system requires investigation.
3. Intrusion Detection and Prevention
Intrusion detection and prevention technologies are designed to identify suspicious or potentially malicious activity.
An Intrusion Detection System (IDS) focuses on detecting activity and generating alerts.
An Intrusion Prevention System (IPS) can go a step further by taking action to block certain detected threats.
These technologies can inspect network traffic for known attack patterns, suspicious behavior, or activity that violates established security policies.
Think of it this way: A firewall controls which traffic is allowed through the door.
Intrusion detection and prevention technologies help identify whether something suspicious is happening with the traffic that’s being allowed through.
4. Network Segmentation
Imagine that every room in an office building could be accessed with the same key.
If someone obtained that key, they could potentially move throughout the entire building.
A poorly segmented network can create a similar problem.
Network segmentation divides a larger network into smaller sections or subnetworks. Access and communication between those areas can then be controlled.
For example, a business might separate:
- Employee devices
- Guest Wi-Fi
- Servers
- Security cameras
- Internet of Things devices
- Sensitive financial systems
- Operational technology
If one part of the network becomes compromised, segmentation can help limit an attacker’s ability to move freely into other areas.
CISA describes segmentation as a way to create boundaries that limit access to devices, data, and applications while restricting communications between networks. Segmentation can also make malicious traffic easier to detect, prevent, and contain.
5. Secure Remote Access and VPNs
Remote and hybrid work changed where employees access company resources.
Employees may connect from home offices, customer locations, hotels, or while traveling.
Secure remote access technologies help protect those connections and control who can remotely access company systems.
A Virtual Private Network, or VPN, is one method businesses have traditionally used to create an encrypted connection between a remote user and company resources.
However, remote access security should involve more than simply providing employees with a VPN.
Businesses should also consider:
- User authentication
- Multi-factor authentication
- Device security
- Access permissions
- Session monitoring
- Which resources remote users actually need
Remote access should give employees what they need to work without unnecessarily exposing the rest of the network.
6. Multi-Factor Authentication
Passwords can be stolen. Employees may reuse them, enter them into phishing websites, or unknowingly expose them through compromised accounts. Multi-factor authentication (MFA) adds another verification requirement before access is granted. Instead of relying entirely on something the user knows, their password, MFA requires another authentication factor.
That means a stolen password alone may not be enough for an attacker to access a protected account.
MFA is particularly important for:
- Remote access
- Cloud applications
- Administrative accounts
- VPN access
- Microsoft 365
- Sensitive business systems
MFA doesn’t replace good password practices or other network security controls, but it creates another obstacle for attackers attempting to use compromised credentials.
7. Network Access Control
Not every device should automatically be allowed to connect to your business network.
Network Access Control (NAC) helps organizations control which users and devices can access network resources.
For example, a business may want to determine:
- Who is connecting?
- What device are they using?
- Is that device authorized?
- Does the device meet security requirements?
- What parts of the network should that user or device be allowed to access?
A company-owned laptop used by an employee may require different access than a visitor’s personal phone.
Network access controls help businesses make those distinctions.
8. Endpoint Security
Every laptop, desktop, and other endpoint connected to the network can potentially become an entry point for an attacker. Endpoint security protects these devices from threats such as malware, ransomware, malicious files, and suspicious activity.
Modern endpoint protection can include technologies such as antivirus, endpoint detection and response, behavioral monitoring, application controls, and automated threat response.
Endpoint security and network security work closely together.
If an employee accidentally opens a malicious attachment, endpoint protection may help detect or stop the threat before it can spread further through the business environment.
9. DNS Security
Every time an employee visits a website, the Domain Name System (DNS) helps translate the website name into the information computers use to locate it. Attackers can take advantage of web traffic by directing users toward malicious websites or infrastructure.
DNS security can help prevent devices from connecting to known malicious or suspicious domains. For example, an employee may click a phishing link that attempts to send them to a malicious website.
Email security may catch the message first. But if it doesn’t, DNS filtering may provide another opportunity to prevent the connection.
This is a good example of why network security works best in layers.
10. Email Security
Email may not immediately seem like network security, but it is one of the most common ways attackers attempt to gain access to business environments.
Phishing emails can be used to:
- Steal passwords
- Deliver malware
- Spread ransomware
- Impersonate executives
- Redirect payments
- Gain access to Microsoft 365 accounts
Email security solutions can help identify malicious links, suspicious attachments, impersonation attempts, spam, and other threats before they reach employees. But technical controls can’t catch every malicious message.
That’s why email security works best alongside MFA, endpoint protection, DNS filtering, employee training, and other security layers.
11. Encryption
Encryption helps protect information by making it unreadable without the appropriate authorization or cryptographic key.
For network security, encryption is particularly important when information is being transmitted between systems.
Think about the sensitive information businesses send every day:
- Customer information.
- Login credentials.
- Financial records.
- Employee information.
- Business documents.
Encrypting data in transit helps protect that information from being read if communications are intercepted. Encryption can also be used to protect data stored on devices and systems, providing another layer of protection for sensitive business information.
12. Patch and Vulnerability Management
Sometimes attackers don’t need to invent a new way into a network. They can exploit a security vulnerability that’s already known. Software vendors regularly release security updates and patches to address vulnerabilities in operating systems, applications, network equipment, and other technologies.
Patch management helps ensure those updates are identified, evaluated, and installed appropriately. Businesses also need to understand what vulnerabilities exist within their environments.
Vulnerability management can include:
- Identifying vulnerabilities
- Evaluating their severity
- Prioritizing remediation
- Installing patches
- Updating software
- Replacing unsupported systems
- Verifying that vulnerabilities have been addressed
Ignoring updates for months or years can leave known weaknesses available for attackers to exploit.
