How to properly send tcp/ip reset packet (RST)? Raw packet creation problem...
Posted on 2004-04-22
I am trying to integrate a feature in my application which allows you to kill active tcp connections with a tcp reset packet. I am using ethereal to monitor packet generation and have been able to craft a packet with the appropriate source ip source port destination ip destination port and the Reset field is 04 which is correct for tcp reset packet but when I try to kill a telnet connection from my machine to my router no luck, connection persists. Solar winds includes a nice utility that works fine and kill the telnet connection. I sniffed the solar winds utility and it appears it grabs the tcp session table from the router and then sends the tcp reset packet to the router (with spoofed source ip of my machine of course). I know how to generate the raw packet with packetx and vb6 which works fine, question is what specific fields are REQUIRED to be correct for a reset to work? I think my problem lies in the ack number window number or sequence number...Any hardcore techies want to try this one??