Which firewall type inspects only the header of the packet to permit or deny traffic based on IP addresses and port numbers?

Which firewall type inspects only the header of the packet to permit or deny traffic based on IP addresses and port numbers?

• A. Packet-Filtering Firewall
• B. Stateful Firewall
• C. NGFW
• D. Unified Threat Management

Answer: (A)

The essential idea here is that some firewalls make decisions by looking only at the packet header. When a firewall inspects just the header, it checks fields like the source and destination IP addresses and the port numbers (and sometimes the protocol) to decide whether to allow or block the traffic, without examining the actual data carried in the packet. This behavior is characteristic of a packet-filtering firewall, which is fast and simple but provides limited protection because it cannot see or analyze payload contents or the context of the connection. In contrast, a stateful firewall tracks active connections and can enforce rules based on the state of a conversation, while a next-generation firewall adds deep packet inspection, application awareness, and often intrusion prevention. Unified Threat Management combines multiple security features in one device, not just traffic filtering. So, the firewall type described is a packet-filtering firewall.