tldr/pages/common/tcpdump.md

tcpdump

Dump traffic on a network

• capture the traffic of a specific interface

tcpdump -i {{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 port

tcpdump -i {{eth0}} src {{192.168.1.1}} dest {{192.168.1.2}} and 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 with today's date

tcpdump -w dumpfile.`date +%Y.%m.%d-%H.%M`.pcap not port 22