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Principles of Operating Systems



                   Notes         to a system that exceeds the maximum capacity. Most of these attacks can be prevented by
                                 upgrading vulnerable software or filtering specific packet sequences.
                                 Resource attacks are the second category of network security threats. These types of attacks are
                                 intended to overwhelm critical system resources such as CPU and RAM. This is usually done
                                 by sending multiple IP packets or forged requests. An attacker can launch a more powerful
                                 attack by compromising numerous hosts and installing malicious software. The result of this
                                 kind of exploit is often referred to zombies or botnet. The attacker can then launch subsequent
                                 attacks from thousands of zombie machines to compromise a single victim. The malicious
                                 software normally contains code for sourcing numerous attacks and a standard communications
                                 infrastructure to enable remote control.
                                 9.3.4.1 Seek and Destroy

                                 The first step in training your staff to identify network security threats is achieving network
                                 visibility. This concept is all rather simple as you cannot defend against or eradicate what you can
                                 not see. This level of network visibility can be achieved with existing features found in devices
                                 you already have. Additionally, you can create strategic diagrams to fully illustrate packet flows
                                 and where exactly within the network you may be able to implement security mechanisms to
                                 properly identify and mitigate potential threats.
                                 You must establish a baseline of normal network activity and patterns in order to detect abnormal
                                 activity and potential network security threats. Mechanisms like NetFlow can be integrated within
                                 your infrastructure to help effectively identify and classify problems. Prior to implementing such
                                 a system, you should perform some sort of traffic analysis to fully comprehend the rates and
                                 patterns of general traffic. In a successful detection system, learning is achieved over a huge
                                 interval which includes the peaks and valleys of network activity.
                                 The best defense against common network security threats involves devising a system that is
                                 adhered to by everyone in the network. Furthermore, you can strengthen your level of security
                                 with reliable software that makes this process much easier.



                                                No program or operating system is built perfectly secured unless your
                                                computer is disconnected from the Internet or unplugged from any connection.



                                 Self Assessment


                                 Multiple choice questions:
                                    1.  A stored procedure is a precompiled sequence of Transact-SQL commands in the ....................
                                      that are executed by calling the procedure within another SQL command  or from the
                                      database driver.

                                       (  a)  database                 (b)  software
                                       (  c)  application              (d)  None of these
                                    2.  .................... from viruses, which are strictly speaking programs that replicate themselves
                                      without your knowledge.
                                       (  a)  Database                 (b)  Robotics
                                       (  c)  Simulation               (d)  Threats originated






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