Network security Vlasov Illia

What is Network security ? Network security consists of the policies and practices adopted to prevent and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources. Network security involves the authorization of access to data in a network, which is controlled by the network administrator. Users choose or are assigned an ID and password or other authenticating information that allows them access to information and programs within their authority. Network security covers a variety of computer networks, both public and private, that are used in everyday jobs; conducting transactions and communications among businesses, government agencies and individuals. Networks can be private, such as within a company, and others which might be open to public access. Network security is involved in organizations, enterprises, and other types of institutions.

Information security management Information security management (ISM) describes controls that an organization needs to implement to ensure that it is sensibly managing these risks. The risks to these assets can be calculated by analysis of the following issues: Threats to your assets: These are unwanted events that could cause the deliberate or accidental loss, damage or misuse of the assets Vulnerabilities: How susceptible your assets are to attack Impact: The magnitude of the potential loss or the seriousness of the event.

Types of Attacks Passive Active Networks are subject to attacks from malicious sources. Attacks can be from two categories: "Passive" when a network intruder intercepts data traveling through the network, and "Active" in which an intruder initiates commands to disrupt the network's normal operation or to conduct reconnaissance and lateral movement to find and gain access to assets available via the network. Passive Wiretapping Port scanner Idle scan Active Denial-of-service attack Buffer overflow Heap overflow Format string attack SQL injection DNS spoofing Man in the middle ARP poisoning VLAN hopping

The most popular Attacks 1. Port Scan A port scanner is an application designed to probe a server or host for open ports. This is often used by administrators to verify security policies of their networks and by attackers to identify network services running on a host and exploit vulnerabilities. A port scan is a process that sends client requests to a range of server port addresses on a host, with the goal of finding an active port; this is not a nefarious process in and of itself. The majority of uses of a port scan are not attacks, but rather simple probes to determine services available on a remote machine.

The most popular Attacks 2.Man in The Middle (MITM) In computer security, a man-in-the-middle attack (often abbreviated MITM, or the same using all capital letters) is an attack where the attacker secretly relays and possibly alters the communication between two parties who believe they are directly communicating with each other. A man-in-the-middle attack can be used against many protocols. One example of man-in-the-middle attacks is active eavesdropping, in which the attacker makes independent connections with the victims and relays messages between them to make them believe they are talking directly to each other over a private connection, when in fact the entire conversation is controlled by the attacker. The attacker must be able to intercept all relevant messages passing between the two victims and inject new ones. This is straightforward in many circumstances; for example, an attacker within reception range of wireless access point can insert himself as a man-in-the-middle.

The most popular Attacks 3. Denial-of-service (DoS) In computing, a denial-of-service attack (DoS attack) is a cyber-attack where the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the Internet. Denial of service is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled. A DoS attack is analogous to a group of people crowding the entry door or gate to a shop or business, and not letting legitimate parties enter into the shop or business, disrupting normal operations.

How to prevent Attack? Use a firewall Firewall is a network security system that monitors and controls the incoming and outgoing network traffic based on predetermined security rules. Use an antivirus Don’t open suspicious links, banners, etc. Don’t install suspicious software on your PC Use proxy server or VPN

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