Simple port scanner

A port scanner is a program which probes a server for open ports by attempting a connection to the server via each port in turn. The program usually then reports which ports were open and which were closed. More complex port scanners, such as Nmap, can probe for other information as well. Port scanning is usually performed by system administrators to verify network security or by attackers looking for an open port through which to compromise the security of a server. Open ports may constitute security vulnerabilities as they allow remote machines to connect. Unexpectedly-open ports may indicate malicious software listening for instructions.-A port scanner is a program which probes a server for open ports by attempting a connection to the server via each port in turn. The program usually then reports which ports were open and which were closed. More complex port scanners, such as Nmap, can probe for other information as well. Port scanning is usually performed by system administrators to verify network security or by attackers looking for an open port through which to compromise the security of a server. Open ports may constitute security vulnerabilities as they allow remote machines to connect. Unexpectedly-open ports may indicate malicious software listening for instructions.