if we scan from inside and outside the network, is it display with the same result?
If the addresses that you scan are routable from the outside and no filtering takes place, then the results would be the same. OS fingerprinting techniques rely on the exchange of packets, by collecting information both from unique patterns and behaviours of each OS's tcp/ip stack, and from checking information graciously provided from software services' banners.
It is not any distinguishable (filterable) kind of inbound traffic used for OS fingerprinting, so if you want any service to be available publicly then this is enough for anyone to take an educated guess about the OS answering. However, since firewalls and nat devices can mess with some of the fingerprinting techniques, you should get more accurate and specific results by scanning from within the network.
The software than Dalight suggested, nmap, implements probably the most efficient method combination for OS fingerprinting and it should be your first choise!
Re: Detect OS using IP address?
12 years 10 months ago #11675