Machine specific tcp data ?

[Parabolic]

I´m wondering about the contents of the tcp stack, and what hardware specific data gets sent out with each tcp package (other then MAC address).

The thing is; I have an account at an satellite ISP that´s limited to 150mb of download quota per month...but i´m able to reset that quota when i log-in (via a HTTPS web page) with another cpu on the local network (all LAN cpu´s go through a single NAT gateway). So, even though the login request always comes from the same ip address, the quota gets reset if the request comes from a different cpu each time. (same thing happens if new OS is installed)

I´ve tried spoofing the mac adress of the machines while logging in, but without success.

: I am therefore wondering if the ISP´s quota tracking software is tracking some element of the tcp stack that is machine/os specific, rather then the given ip address of the gateway machine.

Anyone have any ideas ?

 

[pansophic]

It sounds more like it is a registry setting or local file setting. Those are two things that would go away if you did a reinstall, but your mac address will not change. Plus, your mac address would only go as far as the gateway, then it gets rewritten with the gateway's mac before it is sent to the ISP. There is probably at least 1 additionaly ethernet header rewrite before you reach the web server, maybe more.

Try using Linux and see if it resets as well. If so, I would bet on a local file setting. Now you just have to start checking which files get rewritten each time you log in.


pansophic