Tcp/ip stack debugging

Ok, I have a difficult question again. I’ve asked around, most people don’t even understand what I want… :smiley:

I am looking for a tool which allows me to see which decissions the tcp/ip stack takes in order to drop/allow a connection. Look at this example:

Laptop x with ip address x.x.x.x can connect to machine y. Laptop z with ip address z.z.z.z can connect to machine y, but machine y disconnects/drops the tcp connection sequence by sending a RST.

I want to know why the decission to sent a RST to laptop z is taken.

So I am looking for Unix and/or Windows software which gives me more insight in the above problem.

Anybody any idea? If you know of a place where I might post this question as well, let me know!

http://www.caida.org/projects/internetatlas/viz/SF/

has a script for analyzing tcp flags.

best i could find - i dropped my networking course last sem :wink:

Thanx for taking a look at my question, but this is not what I ment… I am looking for a tool which allows me to the follow the steps the tcp/ip stack of the OS takes. Why does it sent an ‘ACK’ or ‘ACK/NACK’ or ‘RST’, etc.

Perhaps one of these tools ?

Nope, sorry, nothing there…

eek - not the end result - but how it gets there…Unix i can probably find, eventually…windows? pry not. ill look tonight.

best link i found offhand - http://www.private.org.il/tcpip_rl.html