SYN scanning is a tactic that a malicious hacker (or cracker) can use to determine the state of a communications port without establishing a full connection. This approach, one of the oldest in the repertoire of crackers, is sometimes used to perform denial-of-service (DoS) attacks. SYN scanning is also known as half-open scanning.In SYN scanning, the hostile client attempts to set up a TCP/IP connection with a server at every possible port. This is done by sending a SYN (synchronization) packet, as if to initiate a three-way handshake, to every port on the server. If the server responds with a SYN/ACK (synchronization acknowledged) packet from a particular port, it means the port is open. Then the hostile client sends an RST (reset) packet. As a result, the server assumes that there has been a communications error, and that the client has decided not to establish a connection. The open port nevertheless remains open and vulnerable to exploitation. If the server responds with an RST (reset) packet from a particular port, it indicates ___________________________________

Networks comprises of end devices, routing and switching devices, servers, technical control devices etc. The communication and interconnection of these devices makes up a secure and resourceful network.

Attackers can exploit loopholes in networks to steal information. The attackers uses the SYN scanning or cracking technique to implement the DOS or denial of service attack.

DOS is used to flood ports on a server in a network, preventing authorized user access, as they steal information to avoid detection.