A computer arrangement is a accumulation of computer systems and added accretion accouterments accessories that are affiliated calm through advice channels to facilitate advice and resource-sharing a allotment of a advanced ambit of users. Networks are frequently categorized based on their characteristics.
One of the ancient examples of a computer arrangement was a arrangement of communicating computers that functioned as allotment of the U.S. military’s Semi-Automatic Ground Environment (SAGE) alarm system. In 1969, the University of California at Los Angeles, the Stanford Research Institute, the University of California at Santa Barbara and the University of Utah were affiliated as allotment of the Advanced Research Projects Agency Arrangement (ARPANET) project. It is this arrangement that acquired to become what we now alarm the Internet.
Networks are acclimated to:
‘ Facilitate advice via email, video conferencing, burning messaging, etc.
‘ Enable assorted users to allotment a individual accouterments accessory like a printer or scanner
‘ Enable book administration beyond the network
‘ Allow for the administration of software or operating programs on limited systems
‘ Make advice easier to admission and advance a allotment of arrangement users
There are abounding types of networks, including:
‘ Local Area Networks (LAN)
‘ Personal Area Networks (PAN)
‘ Home Area Networks (HAN)
‘ Wide Area Networks (WAN)
‘ Campus Networks
‘ Metropolitan Area Networks (MAN)
‘ Enterprise Private Networks
‘ Backbone Networks (BBN)
‘ Global Area Networks (GAN)
‘ The Internet
Early Internet – History of PC networking
At the aforementioned time as the bookish and analysis communities were creating a arrangement for accurate purposes, a lot of alongside action was traveling on abroad architecture computer networks as well.
The afterward is an agenda of cogent computer arrangement developments:
In the backward 1950s, aboriginal networks of communicating computers included the aggressive alarm arrangement Semi-Automatic Ground Ambiance (SAGE). In 1960, the bartering airline catch arrangement semi-automatic business analysis ambiance (SABRE) went online with two affiliated mainframes. In 1962, J.C.R. Licklider developed a alive accumulation he alleged the “Intergalactic Computer Network”, a forerunner to the ARPANET, at the Advanced Analysis Projects Agency (ARPA).In 1964, advisers at Dartmouth developed the Dartmouth Time Sharing Arrangement for broadcast users of ample computer systems. The aforementioned year, at Massachusetts Institute of Technology, a analysis accumulation accurate by General Electric and Bell Labs acclimated a computer to avenue and administer blast connections. Throughout the 1960s, Leonard Kleinrock, Paul Baran, and Donald Davies apart developed arrangement systems that acclimated packets to alteration advice amid computers over a network. In 1965, Thomas Marill and Lawrence G. Roberts created the aboriginal advanced breadth arrangement (WAN). This was an actual forerunner to the ARPANET, of which Roberts became affairs manager. Also in 1965, the aboriginal broadly acclimated blast about-face that implemented accurate computer ascendancy was alien by Western Electric. In 1969, the University of California at Los Angeles, the Stanford Analysis Institute, the University of California at Santa Barbara, and the University of Utah were affiliated as the alpha of the ARPANET arrangement application 50 kbit/s circuits. In 1972, bartering casework application X.25 were deployed, and after acclimated as an basal basement for accretion TCP/IP networks. In 1973, Robert Metcalfe wrote an academic announcement at Xerox PARC anecdotic Ethernet, a networking arrangement that was based on the Aloha network, developed in the 1960s by Norman Abramson and colleagues at the University of Hawaii. In July 1976, Robert Metcalfe and David Boggs appear their cardboard “Ethernet: Broadcast Packet Switching for Local Computer Networks” and collaborated on several patents accustomed in 1977 and 1978. In 1979, Robert Metcalfe pursued authoritative Ethernet an accessible standard. In 1976, John Murphy of Datapoint Corporation created ARCNET, a token-passing arrangement aboriginal acclimated to allotment accumulator devices. In 1995, the manual acceleration accommodation for Ethernet was added from 10 Mbit/s to 100 Mbit/s. By 1998, Ethernet accurate manual speeds of a Gigabit. The adeptness of Ethernet to calibration calmly (such as bound adapting to abutment new cilia optic cable speeds) is an accidental agency to its connected use today.
Computer network security issues
Network security deals with the requirements needed for a company, organization or a network administrator to help in protecting the network, computer systems and the resources that are network accessible. They are protected from any unauthorized entry, malicious components as well as monitoring continuously, consistently and measuring the effectiveness or lack of effectiveness of the network.
Network security is a major concern of every company that has a computer and is connected to a network. A network security that has been compromised means that a competitor or any hacker can gain entry to the sensitive or critical data and they may delete or make off with the information resulting in data loss or complete system destruction. The terms information security and network security are most of the time used to represent the same meaning. Network security, though, is more specifically taken as the provision protection from outside intruders. The process of network security begins from the authentication of any user who logs in with the appropriate password and user name which is ‘one factor authentication’. There is another method of authentication known as ‘two factor’ where when one is using an item like an ATM card or mobile phone and another three factor authentication can also be used where a body part is used like a retinal scan or fingerprint. When authentication has been verified, there is a firewall that decides, which programs or services are allowed for network users to access. This component may be effective in the ability to prevent any unauthorized access but it fails to check harmful contents like computer worms that are transmitted across the network. An IPS or intrusion prevention system is able to detect and stop the activities of this sort of malware. The firewall and IPS settings are created by the network’s System Administrator who also installs a viable antivirus system, which is up-to-date.
While many causes exist for security problems, at least three types of fundamental weaknesses open the door to security problems.
Every technology has some known or unknown inherent weaknesses, or vulnerabilities that can be exploited by a sufficiently motivated troublemaker. Some weaknesses are publicized widely in the media because they’re associated with a well-known product. Don’t fall into the faulty logic that because you don’t hear about the other products, they must be secure. Just because no one cares enough to hack a product, doesn’t mean it’s necessarily secure.
Policy weakness is a catchall phrase for company policies, or a lack of policies, that inadvertently lead to security threats to the network system. Chapter 2 covers in detail the importance and implementation of a written security policy, which is the essential foundation of a good security implementation. The following examples are some of the policy issues that can negatively impact a business computer system:
‘ No written security policy
‘ Lack of disaster recovery plan
‘ No policy for software and hardware additions
Many network devices have default settings that emphasize performance or ease of installation without regard for security issues. Installation without adequate attention to correcting these settings could create serious potential problems. Some common configuration issues include the following:
‘ Ineffective access control lists failing to block intended traffic.
‘ Default, missing, or old passwords
‘ Unneeded ports or services left active
‘ User IDs and passwords exchanged in clear text
‘ Weak or unprotected remote access through the Internet or dial-up services.
For protection of computer systems against unauthorized interference in processes of their functioning and information the following main protector methods are used:
‘ Identification (naming and identification), authentication (authenticity confirmation) users of system
Identification is, on the one hand, assignment of individual names, numbers or
special devices (identifiers) to subjects and system objects, and, on the other
hand, is their identification by the unique identifiers assigned by it. Identifier
Authentication is a confirmation of authenticity of identification of the subject or
system object. The purpose of authentication of the subject is to be convinced
that the subject is who was identified.
‘ Access differentiation of users to system resources and authorization
‘ (assignment of rights) to users;
‘ Registration and notification about the events occurring in system;
‘ Cryptography of stored and transferred on data links;
Cryptography methods of protection are based on possibility of realization of some operation of conversion of the information which can be fulfilled by one or several users of the system possessing some secret key without which it is impossible to carry out this operation.
‘ The integrity and authenticity control of the data;
‘ Revealing and neutralization of operations of computer viruses;
‘ Overwriting of the remainder information on data carriers;
‘ Identifying the vulnerabilities (weak places) of systems;
‘ Computer network isolation (traffic filtering, concealment of internal structure
‘ and addressing, etc.);
‘ Detection of attacks and operative reaction;