tcpdump: Difference between revisions

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# tcpdump -D
# tcpdump -D
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=== Interface, file size, rotation, output file===
=== Interface, user, file size, rotation, output file===
<syntaxhighlight lang="bash">
<syntaxhighlight lang="bash">
# tcpdump -i eth0 -Z root -C300 -W4 -w $HOSTNAME-tcpdump.pcap
# tcpdump -i eth0 -Z root -C300 -W4 -w $HOSTNAME-tcpdump.pcap

Revision as of 16:41, 10 May 2025

Tcpdump prints out a description of the contents of packets on a network interface that match the boolean expression. Many flags need root permissions to run.

Install

# apt install tcpdump

Flags

Tcpdump flags
Flag Description
-D List all interfaces.
-i Interface, eth1, any.
-C Max file size to save, -C100, 100 meg, all files will have subsequent numbers.
-W Limit the number of files, -W5, use with -C.
-w Output file name.
-Z User, -Z root.
-r Read the output file.
-c Packets captured, -c100.

List all interfaces

# tcpdump -D

Interface, user, file size, rotation, output file

# tcpdump -i eth0 -Z root -C300 -W4 -w $HOSTNAME-tcpdump.pcap
# tcpdump -r zyklonB-tcpdump.pcap