Inject raw fragmented packets

I'm trying to inject a fragment packet and i can't. I see that if i have one udp packet witch has been split to two Ip packets i can't inject only the second part, my operation system (windows Xp) seems to wait for the first part before it injects the two fragmented packets. I don't have routers in the way or something like that, because I'm sending the packets to another computer which connected to my computer in cross. I have tried it with 3 different kinds of NIC. I'm sure that the packets are waiting in my computer (the sender) I have proved it if you want I will post the experiment. I have tried to play with 开发者_运维知识库the flags and nothing. If i try to send only the first part on one computer it seems to work (weird) but I can't explain it. please don't tell my to switch to Linux it is really problematic.

Thank you all. It is really important.

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If the use of Windows is not crucial, I have successfully used tcpreplay on a Linux machine, run as root, to read arbitrary packets from a pcap file and send them out on a network interface.

http://tcpreplay.synfin.net

The tcpreplay web page says that it is available for Cygwin running on Windows as well, although I have not tried that version before.

http://www.cygwin.com