Thanks for the idea. However, looking over the netfilter information, it seems that I can only specify certain TCP fields to mangle. I don't see where I can manipulate the checksum and/or data fields. Am I missing something? >You can obviously use Netfilter (netfilter.kernelnotes.org) with queueing >rules in the OUTPUT chain. > >On Thu, 26 Apr 2001, Karl Williams wrote: > >> >> I need to replace the data field and the checksum field in a tcp packet with other information (not related to the socket or socket buffer). >> >> >Where is the packet originating from? Does it originate from a program on >> >your computer, or some other machine addressed to your computer, or just >> >forwarded through your computer? >> >> The packet itself is generated on my own machine. I assume it's using the TCP subroutines in the .../net/ipv4 directory. Get 250 color business cards for FREE! http://businesscards.lycos.com/vp/fastpath/ - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org