This content about technology of port scanner working.
Server can have lots of different services, tools, utils. But need to know how to connect to one needed service - not to all other, and give-request some info.
Technology of division server connection zones by services - it's ports connections, each service linked with some one or several ports and when need to connect to it,
other server connecting to some port that linked with needed service on destionation server box.
Technology of port scanner (free online port scan tool
) working is very easy. User giving IP or Domain name, tool resolving it, and trying to connect to each port from user's list - doing open port scan
If during connection timeout destination not answering - port is closed, if connection success - remote port scan
A port scan is a series of messages sent by someone attempting to break into a computer to learn which computer network services, each associated with a "well-known" port number, the computer provides. Port scanning, a favorite approach of computer cracker, gives the assailant an idea where to probe for weaknesses. Essentially, a port scan consists of sending a message to each port, one at a time. The kind of response received indicates whether the port is used and can therefore be probed for weakness.