Is there any way how to find out any machines behind NAT?

[StandaK]

I have two computers connected to Internet using NAT (running on one of them). Can ISP somehow find out that I have next computer behind the one that is connected directly and running NAT? The told me they can, I don't believe them...

Any suggestion?

TIA Standa.

 

[Wizardsden]

no. not unless your ISP hacks your firewall and since that would be illegal they won't do it.

 

[StandaK]

And what about logging source MAC adresses? I think this is the way how ISP can find out I'm running NAT - packets coming from my machine behind NAT will have different MAC from packets coming from machine running NAT...Am I right?

 

[ChrisHirst]

If that were the case thousands of SMEs and individuals around the world are in trouble including me. I have 5 machines connected to what is in theory a single user DSL connection. And of course the ISPs are going to investigate the untold millions of packets crossing their routers every hour of every day.
The source address in the packet will only be from the device connected to the internet anyway otherwise there would little point in employing a NAT device.

look up How NAT works in Winroute help or do a internet search.


Chris.


Indifference will be the downfall of mankind, but who cares?

 

[noxon]

There is one way the isp can get the number of pc's behind your NAT. But the pc's have to run simultaneously for this to work. The trick is, that every ip packet have a number, so that the destination pc can put them together in the right order. Windows is using increasing numbers to index the ip packets. Now. If two pc's sending ip packets there are to different rows of numbers. Let's say pc1 is sending packets with the number 1,2,3,4 and pc2 is sending packets 101,102,103. The ISP can now conclude that there are two pc's behind your NAT. It's not proof since the numbers aren't have to be incresing but windows does. FreeBSD for example uses random numbers.