I have a pcap file to replay. I want to rewrite packet payload to include a timestamp. How can I do that with tcpreplay or tcprewrite? Is there a default option or should I impl
If you are not bound to a command line tool, checkout netdude. It is GTK application which allows you to edit a packet trace using just a few clicks.
Here is a screenshot that shows the dialog to edit the TCP header fields.
(source: sourceforge.net)
The accompanying library libnetdude is the core of netdude. Write your own tool with it if the GUI provided by netdude does not meet your needs.