tldr/pages/common/tcpdump.md

# tcpdump

> Dump traffic on a network.
> Homepage: <https://www.tcpdump.org>.

- List available network interfaces:

`tcpdump -D`

- 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 destination port:

`tcpdump -i {{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}} not port {{22}}`

- Read from a given dump file:

`tcpdump -r {{dumpfile.pcap}}`