Port Scanner Tools
About Port Scanner
Basically, a port scanner is a software application designed to check a server or host for opening ports. This utility will send messages to individual TCP or UDP ports on a network gateway device to get information. The Network administrators usually use this tool to validate security policies of their networks and the attackers also use this software to identify running services on a host with the unsecured gateway to break in the network.
Transmission Control Protocol
(TCP) and Internet Protocol (IP) are two different network protocols. However, TCP and IP are used together, and TCP/IP has become the standard terminology in network.
IP method is located on the Network layer (Layer 3) in the OSI model, whereas TCP is located to the Transport layer (Layer 4) in OSI model. On the other hand, TCP/IP refers to network communications where the TCP transport protocol is used to deliver data across networks by using IP method.
UDP (User Datagram Protocol)
is a simple OSI transport protocol for client/server layer network applications based on Internet Protocol (IP). UDP is one of the oldest network protocols since it was introduced in 1980.
UDP is usually used in video conferencing applications or computer games, especially tuned for real-time performance.