A Denial-of-Service Attack (DoS Attack) is a Cyber Attack . Denial of service is characteristically proficient by flooding the targeted machine or resource with excessive requirements in an endeavor to surplus systems. It is any type of attack where the hackers try to prevent valid users from the service accession. In a DoS attack, the attacker generally sends too much messages asking the server to substantiate requests that have unsound return addresses. The server may be unable to discover the return address of the attacker when sending the substantiation consent.
When the server closes the connection, the attacker sends more substantiation messages along with invalid return addresses. Hence, the process of authentication and server wait will begin again. A DoS attack can be prepared in a numerous ways. The basic types of attack comprises: Flooding the network to prevent justifiable network traffic, unsettling the connections between two machines, preventing admittance to a service, Preventing a user from accessing the service, distracting a service to a specific system or individual, resetting of TCP sessions.
Another alternative of the DoS is the smurf attack. it involves emails with automatic responses. DoS attacks can cause the following problems:Ineffective services,Inaccessible services,Interruption of network traffic & Connection interference.