Learn tcpdump Filter Quick Guide

Table of Contents

Tcpdump is a powerful command-line packet analyzer. It allows us to display TCP/IP and other packets being transmitted or received over a network. We collect 30 tcpdump filters to help you learn tcpdump quickly.

30 tcpdump examples to filter packets

How to filter MAC addresses using tcpdump?

Use the host option on the tcpdump command to limit output to a specific MAC address: tcpdump ether host aa:bb:cc:11:22:33

How to filter tcpdump on a specific port ?

Use the port option on the tcpdump command to specify a port: tcpdump ether port 80

How to read tcpdump output?

There is a read option on tcpdump, which is represented by the switch -r as in: tcpdump -r file_path_and_name

How to capture packets with tcp flag filter?

FIN, ACK = 17 (1 + 16)

SYN, ACK = 18 (2 + 16)

PSH, ACK = 24 (8 + 16)

FIN, PSH = 9 (1 + 8)

FIN, PSH, ACK = 25 (1 + 8 + 16)

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David Cao
David Cao

Hey there! I am David, a Cloud & DevOps Enthusiast and 18 years of experience as a Linux engineer. I work with AWS, Git & GitHub, Linux, Python, Ansible, and Bash. I am a technical blogger and a Software Engineer, enjoy sharing my learning and contributing to open-source.