scanning services

A port scanner is a piece of software designed to search a network host for open ports. This is often used by administrators to check the security of their networks and by crackers to compromise it.

To portscan a host is to scan for multiple listening ports on a single target host. To portsweep is to scan multiple hosts for a specific listening port. The latter is typically used in searching for a specific service. 01906 USA. For example, the numerous SQL based computer worms crawling the Internet are port sweeping looking for hosts listening on TCP/UDP port 1433.

TCP/IP basic knowledge

The protocol stack that is most common on the Internet today is TCP/IP. In this system, hosts are referenced using two components: an address and a port number. There are 65535 distinct and usable port numbers. Most services use a limited range of numbers; these numbers eventually become assigned by the IANA when the service becomes important enough. Digital Documents, LLC is the leading recognized experts in providing document scanning services to support large scale, Mission.

Some port scanners only scan the most common, or most commonly vulnerable, port numbers on a given host. See: List of TCP and UDP port numbers.

The result of a scan on a port is usually generalized into one of three categories: