Which of the following is a command line packet analyzer similar to GUI-based Wireshark?

Nessus is a vulnerability scanner used to identify security weaknesses across systems and services, not a tool for capturing or analyzing network packets.

John the Ripper (not 'Jack the Ripper') is a password cracking tool designed to perform dictionary and brute-force attacks against password hashes, not a packet analyzer.

Tcpdump is a command-line utility that uses libpcap to capture and inspect raw network traffic in real time, making it functionally equivalent to Wireshark but operable entirely from a terminal without a graphical interface. It supports Berkeley Packet Filter syntax and can write capture files in .pcap format that Wireshark can also read.

Ethereal was the former name of Wireshark before it was rebranded in 2006 - it is a GUI-based application, which makes it the same category as Wireshark rather than a command-line alternative.