A network technician is trying to determine the source of an ongoing network based attack. Which of the following should the technician use to view IPv4 packet data on a particular internal network…

A proxy server acts as an intermediary for client requests, forwarding and potentially filtering traffic, but it does not primarily capture and display raw packet data for analysis on a network segment.

A protocol analyzer, also known as a packet sniffer, is a software or hardware tool specifically designed to capture, display, and analyze network traffic (packets) passing over a network segment. This capability allows the technician to examine IPv4 packet headers and payloads in detail, revealing information like source/destination IP addresses, protocols, and data that can pinpoint an attack's origin.

A network switch forwards frames based on MAC addresses and does not inherently provide tools to view or analyze the raw packet data traveling through it, although it can be configured for port mirroring to send traffic to a protocol analyzer.

A firewall primarily monitors and controls network traffic based on security rules, logging blocked or allowed connections, but its main function is not to perform deep packet analysis for general viewing or attack source identification in the same manner as a dedicated protocol analyzer.