tcpdump command dump traffic on a network in real time. It prints out a description of the contents of packets on a network interface.
How do I capture network packets to a file?
By default traffic is dumped on a screen. To capture these packets to a file, enter the following command as the root user:
# tcpdump -i eth0 -w traffic.eth0
How do I read packets from a file?
The -w flag causes it to save the packet data to a file called traffic.eth0 for later analysis, and/or with the -r flag, which causes it to read from a saved packet file rather than to read packets from a network interface:
# tcpdump -r traffic.eth0
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{ 5 comments… read them below or add one }
Nice tip, Vivek! Also it would be useful to send these captured packets with tool Bit-twist.
An example of it’s usage is available here.
Artem,
Thanks for sharing Bit-Twist. I will check it out :)
does tcpdump support tcp packet reassembly?? if not how can reassembly be implemented?
Many Tks.
also the captured can also be viwed in wireshark. :):)
Thx for the tip! Well we can also use AthTek NetWalk to help capture Linux network packets