tldr/pages/common/tcpdump.md

tcpdump

Dump traffic on a network. More information: https://www.tcpdump.org.

• List available network interfaces:

tcpdump {{[-D|--list-interfaces]}}

• Capture the traffic of a specific interface:

sudo tcpdump {{[-i|--interface]}} {{eth0}}

• Capture all TCP traffic showing contents (ASCII) in console:

tcpdump -A tcp

• Capture the traffic from or to a host:

tcpdump host {{www.example.com}}

• Capture the traffic from a specific interface, source, destination and destination port:

sudo tcpdump {{[-i|--interface]} {{eth0}} src {{192.168.1.1}} and dst {{192.168.1.2}} and dst port {{80}}

• Capture the traffic of a network:

tcpdump net {{192.168.1.0/24}}

• Capture all traffic except traffic over port 22 and save to a dump file:

tcpdump -w {{dumpfile.pcap}} port not {{22}}

• Read from a given dump file:

tcpdump -r {{dumpfile.pcap}}