Control Access
Network access controls determine which users, devices, and applications may connect to protected systems and resources.
NETWORK DEFENSE ACTIVE
CYBERSECURITY TOPIC
Understand and Defend Computer Networks
Network security protects computers, servers, mobile devices, cloud systems, and sensitive information as data travels through wired and wireless networks.
24/7
Monitoring
7
OSI Layers
3
Security Goals
NETWORK SECURITY FOUNDATIONS
What Is Network Security?
Network security is the combination of technologies, policies, configurations, and monitoring processes used to prevent unauthorized access, misuse, disruption, and data exposure.
Monitor Traffic
Network monitoring examines connections, logs, traffic patterns, and device behavior to identify suspicious activity.
Protect Data
Encryption and secure communication protocols protect information as it travels between devices and online services.
Maintain Availability
Reliable network designs help authorized users continue accessing important systems, applications, and information.
LIVE TRAFFIC MONITOR
Network Activity Overview
Packets Inspected
18,452
Last hour
Trusted Connections
98.7%
Normal activity
Events Reviewed
143
Automated analysis
Defense Status
Protected
Controls operational
DEFENSE IN DEPTH
Important Network Security Layers
Strong network protection uses several overlapping security controls. If one layer misses an event, another layer may detect, block, contain, or record it.
PERIMETER CONTROL
Firewalls
Firewalls inspect network traffic and apply rules that allow, restrict, or block connections between systems.
CONTAINMENT
Network Segmentation
Segmentation divides a network into smaller security zones to reduce unnecessary access and limit incident spread.
IDENTITY
Access Control
Authentication and authorization help verify users and devices before allowing them to access network resources.
VISIBILITY
IDS and IPS
Intrusion detection and prevention systems identify suspicious activity and may alert, block, or contain it.
CONFIDENTIALITY
Encryption
Secure protocols, encrypted wireless connections, and VPNs help protect information while it moves across networks.
DETECTION
Logging and Monitoring
Logs and monitoring tools help security teams investigate unusual connections, alerts, and network behavior.
COMMON NETWORK RISKS
Threats Network Defenders Watch For
Understanding common network risks helps organizations select effective security controls and identify unusual activity.
01
Unauthorized Access
An unapproved user or device attempts to connect to protected network systems, services, or sensitive information.
02
Malicious Software
Compromised devices may communicate across a network, disrupt operations, or attempt to reach additional systems.
03
Traffic Interception
Unprotected communications may be observed or changed when insecure protocols or unsafe networks are used.
04
Service Disruption
Excessive or abnormal network traffic can consume resources and prevent legitimate users from accessing services.
NETWORK SEGMENTATION
Separate Systems to Reduce Risk
A flat network gives connected systems broad access to one another. Segmentation creates controlled security zones, making it easier to protect sensitive services and contain suspicious activity.
- Separate guest, employee, server, and management traffic.
- Restrict communication between zones with firewall rules.
- Monitor high-value systems more closely.
- Limit lateral movement during a security incident.
Internet
Firewall
User Zone
Server Zone
Guest Zone
SECURE NETWORK CHECKLIST
Network Security Best Practices
Change Default Credentials
Replace default usernames and passwords on routers, access points, firewalls, and managed devices.
Install Security Updates
Keep network hardware, operating systems, applications, and device firmware supported and updated.
Use Secure Protocols
Prefer encrypted services such as HTTPS, SSH, secure VPN technologies, and modern wireless protection.
Apply Least Privilege
Give users, applications, and devices only the network access needed to perform approved tasks.
Review Logs and Alerts
Review unusual connections, authentication failures, configuration changes, and security events.
Back Up Configurations
Maintain protected copies of important device settings and document how the network is designed.
CYBERSECURITY CAREERS
Careers in Network Security
Network security professionals combine networking knowledge, system administration, monitoring, incident response, and cybersecurity risk management.
Network Security Analyst
Reviews network traffic, alerts, device configurations, and vulnerabilities to protect organizational systems.
Security Engineer
Designs and maintains firewalls, secure network architecture, monitoring systems, and defensive controls.
Network Administrator
Manages network availability, devices, access permissions, updates, troubleshooting, and secure configurations.
SOC Analyst
Monitors security alerts, investigates suspicious events, documents findings, and supports incident response.
CONTINUE LEARNING
Build a Stronger Cybersecurity Foundation
Explore more Cybersecurity Life topics to understand how networks, systems, applications, people, and data work together.