tcpdump lets you view network packets being sent and received

happy little stick figure: it’s not the easiest to use but it’s usually installed (heart)

-n

don’t try to resolve IP addresses/ports to DNS/port names. makes it run faster

i wlan0

Which network interface to capture packets on

person: I often use “-i any” to make sure I’m not missing any packets!

-w file.pcap

Write packets to a file for later analysis with tcpdump/tshark/wireshark/another tool

pcap is short for “packet capture”

-A

print packet contents, not just headers. Nice if you want to quickly see what a few packets contain.

-c 1000000

Only capture a limited count of packets.

person: I use it with -w so I don’t accidentally fill up my disk!