bash
4 lines · 1 tab
Kai Nakamura
Apr 2026
1 tab
#!/usr/bin/env bash
tcpdump -i eth0 host 10.10.20.15 -w suspect-host.pcap
tcpdump -i eth0 port 443 and host api.example.com
tcpdump -i eth0 'tcp[tcpflags] & (tcp-syn|tcp-fin|tcp-rst) != 0'
1 file · bash
Explain with highlit
Packet capture is most useful when it is scoped enough to answer a question quickly. I capture by host, port, subnet, or flag pattern rather than grabbing everything and hoping to sort it out later. Storage, privacy, and time all argue for precision.
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