What information can I get from an IP address?

Question

If you have IP addresses of a set of computers (in a LAN), what other information can be deduced from them? For instance, is there a way to find out what operating system the computer behind each IP is running?

Answer 1

That depends if you mean passively or actively. Passively (that is, by not attempting to connect to or scan the IP itself) you can see exactly what information is available from an IP from my service at http://ipinfo.io . It includes rough geolocation, hostname, and network owner. Here the data for Google's public DNS IP:

$ curl ipinfo.io/8.8.8.8
{
  "ip": "8.8.8.8",
  "hostname": "google-public-dns-a.google.com",
  "loc": "37.385999999999996,-122.0838",
  "org": "AS15169 Google Inc.",
  "city": "Mountain View",
  "region": "California",
  "country": "US",
  "phone": 650
}

If you want to take the active approach you can find out much more. Tools like nmap will tell you exactly what services are running and be able to make a good guess at the OS that's running.

Answer 2

From the IP address you can often get:

• a rough geographic location for the machine ( http://www.ip2location.com/ )
• the name of the company operating the network ( whois )

but that's about it.

However ... From a full TCP session, you can deduce other things based on exactly how it behaves, what values in chooses for certain header fields, etc. NMAP has a "fingerprint" system that makes pretty good guesses as to the operating system the machine is running.

Answer 3

From my service - ipdata.co - you can get the geolocation, organisation, currency, timezone, calling code, flag and Tor Exit Node status data from any IPv4 or IPv6 address.

It also has 10 global endpoints each able to handle >800M calls a day!

curl https://api.ipdata.co/70.70.70.70
{
    "ip": "70.70.70.70",
    "city": "",
    "region": "",
    "region_code": "",
    "country_name": "Canada",
    "country_code": "CA",
    "continent_name": "North America",
    "continent_code": "NA",
    "latitude": 43.6319,
    "longitude": -79.3716,
    "asn": "AS6327",
    "organisation": "Shaw Communications Inc.",
    "postal": "",
    "currency": "CAD",
    "currency_symbol": "$",
    "calling_code": "1",
    "flag": "https://ipdata.co/flags/ca.png",
    "emoji_flag": "\ud83c\udde8\ud83c\udde6",
    "time_zone": "",
    "is_eu": false,
    "suspicious_factors": {
        "is_tor": false
    }
}⏎ 

Answer 4

So many options. There is also https://ifconfig.co , with a very developer focussed website.