Retain information by an IP address

Question

What information can I get only by having an IP address ?

For example: Computer name, domain name, dns servers (if it's a server) etc.

Thank you.

Answer 1

The only things you can do are:

1. tracert / traceroute to the IP address e.g. traceroute 8.8.8.8 This will tell you the path traffic tends to take from your host to the remote host. You can find out upstream providers by using this method.

2. whois the ipaddress e.g. whois 8.8.8.8 This will who owns the netblock of the address, and their contact details.

3. reverse dns lookup. There are some sites on the internet which provide this service.

Answer 2

Using nmap (http://nmap.org/) you can find a whole lot more about any given host. There are many options avaiable, but the most popular would be:

Scan for remote OS:

nmap -v -A 8.8.8.8

Not working? Guess the remote OS:

nmap -v -O --osscan-guess 8.8.8.8

Scan firewalled host:

nmap -PN 8.8.8.8

Scan for typical services, i. e. those below port 1025:

nmap -sV 8.8.8.8

And of course, scan any old port(use "*" for all ports):

nmap -p 12345 8.8.8.8