nmap

[Bob182]

hello,

I'm a newbie at networking and I have a question:
how can I nmap and get the OS specification of a computer, instead of the specification of its isp router ? It would appear to me that I have to use the ip address of the isp computer's network card (the one that is displayed on a web forum, for instance) rather than the one found on ifconfig, which is non routable, but then wouldn't I be nmaping the router rather than the computer itself?

Thanks.

[Lazydog]

Are you trying to nmap a device that is behind a NAT router? Are you also behind that same NAT router?

[Bob182]

Hi,
sorry for the late answer I didn't notice there had been a question.
I'm not sure about the terminology, because I'm not an expert, but I don't think this is what you would call a NAT router. In any case one thing I'm sure of is that I'm not behind the same item, whatever it is called.
Basically it's just an item that allows you to connect to the Internet and that is provided by the ISP, an ADSL modem. But it does indeed some IP translation, because the ip that is displayed in a web forum for instance is not the same as the one that is displayed in ifconfig.
So my question is how do I nmap the computer that is using that device to connect to the internet ? I'm pretty sure I shouldn't use the ip in ifconfig, because it's non routable, but then if I am to use the ip that is displayed in a web forum (which I'm guessing is the isp router ip address (?)), wouldn't I be nmaping the router instead ?

Thanks

[rcgreen]

If you are working from some place outside your own home,
"out on the internet" from a friend's house, from work, or
whatever, you cannot nmap that computer. It is completely
firewalled by the router.