Firewall network security role – UGC NET Question

A firewall enforces a security policy by examining incoming and outgoing packets and deciding whether to allow or block them. It can be configured to restrict access to certain ports, addresses or protocols, thereby reducing exposure to attacks. Firewalls are a key component of network perimeter defence in organisations. Thus the protective mechanism described in the stem is a firewall.

Option A:
Option A, router, primarily handles routing packets between networks and may include some filtering features, but routing is its main purpose. Without specific security configurations, it does not offer comprehensive protection.

Option B:
Option B, gateway, refers to a device or software that connects networks using different protocols and is focused on translation and connectivity rather than security enforcement alone.

Option C:
Option C, antivirus scanner, inspects files and memory for malicious code on individual hosts rather than controlling network traffic flows across a boundary. Its scope is different from that of a firewall.

Option D:
Option D is correct because firewalls are explicitly defined as systems that monitor and regulate network connections according to configured rules, matching the wording in the question.