Cisco Certified Support Technician (CCST) CybersecurityNetwork SecurityEasy
A network administrator is implementing a security measure to prevent unauthorized access to a company's internal network from the internet. Which of the following network security devices is primarily designed to filter traffic based on predefined rules and enforce security policies at the network perimeter?
- ALoad Balancer
- BNetwork Access Control (NAC)
- CIntrusion Detection System (IDS)
- DFirewall
Show answer & explanationAnswer & explanation
Correct answer: D. Firewall
A firewall is a network security device that monitors and filters incoming and outgoing network traffic based on an organization's previously established security policies. It acts as a barrier between a trusted internal network and untrusted external networks, such as the internet.
Why the other options are wrong
- A. A load balancer distributes network traffic across multiple servers to optimize resource utilization, not primarily for security filtering.
- B. NAC controls who can access the network based on device compliance and user identity, typically after initial network access.
- C. An IDS monitors network traffic for suspicious activity and alerts, but does not actively block traffic.
Firewall
A network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.
- Acts as a barrier between trusted and untrusted networks.
- Filters traffic based on IP addresses, ports, and protocols.
- Can be hardware, software, or cloud-based.
Memory trick: Firewalls Fend off Foreigners Fast.