Footprinting is the technique of gathering information about computer systems and the entities they belong to. This is done by employing various computer security techniques, as:

• DNS
  Domain name system
  The Domain Name System is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities...
  
   queries
• Network enumeration
• Network queries
• Operating system
  Operating system
  An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
  
   identification
• Organizational queries
• Ping
  Ping
  Ping is a computer network administration utility used to test the reachability of a host on an Internet Protocol network and to measure the round-trip time for messages sent from the originating host to a destination computer...
  
   sweeps
• Point of contact queries
• Port Scanning
• Registrar queries (WHOIS
  WHOIS
  WHOIS is a query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block, or an autonomous system, but is also used for a wider range of other information. The protocol stores...
  
   queries)
• SNMP queries
• World Wide Web
  World Wide Web
  The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...
  
   spidering

When used in the computer security lexicon, "footprinting" generally refers to one of the pre-attack phases; tasks performed prior to doing the actual attack. Some of the tools used for footprinting are Sam Spade

Sam Spade (software)

Sam Spade is the name of a Windows software tool designed to assist in tracking down sources of e-mail spam. It is also the name of a free web service that provides access to similar online tools. The Sam Spade utility was authored by Steve Atkins in 1997. It is named after the fictional character...

, nslookup

Nslookup

nslookup is a network administration command-line tool available for many computer operating systems for querying the Domain Name System to obtain domain name or IP address mapping or for any other specific DNS record.-Background:...

, traceroute

Traceroute

traceroute is a computer network diagnostic tool for displaying the route and measuring transit delays of packets across an Internet Protocol network. Traceroute is available on most operating systems....

, Nmap

Nmap

Nmap is a security scanner originally written by Gordon Lyon used to discover hosts and services on a computer network, thus creating a "map" ofthe network...

 and neotrace.

See also

• digital footprint
  Digital footprint
  A digital footprint is a trail left by an entity's interactions in a digital environment; including their usage of TV, mobile phone, internet and world wide web, mobile web and other devices and sensors...
  
  
• Nmap
  Nmap
  Nmap is a security scanner originally written by Gordon Lyon used to discover hosts and services on a computer network, thus creating a "map" ofthe network...
  
  
• Network Security
  Network security
  In the field of networking, the area of network security consists of the provisions and policies adopted by the network administrator to prevent and monitor unauthorized access, misuse, modification, or denial of the computer network and network-accessible resources...
  
  
• WHOIS
  WHOIS
  WHOIS is a query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block, or an autonomous system, but is also used for a wider range of other information. The protocol stores...
  
  
• nslookup
  Nslookup
  nslookup is a network administration command-line tool available for many computer operating systems for querying the Domain Name System to obtain domain name or IP address mapping or for any other specific DNS record.-Background:...
  
  
• jsky
• Visual Traceroute