The colle ction of addresses in the network is called the address space Examples of telecommunications networks are: The computer networks The Internet telephone network The global Telex network The aeronautical ACARS network The need for secure network access has never been greater. In today’s divers e workplaces, consultants, contractors, and even guests require access to network resource s over the same LAN connections as regular employees, who may themselves bring unmanage d devices into the workplace.
As data networks become increasingly indispensable in daytoday business operations, the possibility that unauthorized people or devices will gain acces s to controlled or confidential information also increases. The best and most secure solution to vulnerability at the access edge is to use the intelligence of the network. IEEE 802. IX provides portbased access control using authenticati on, but uthentication alone does not guarantee the confidentiality and integrity of d ata on the LAN. While physical security and enduser awareness can mitigate threats to data o nan IEEE 802. Xauthenticated LAN, there may be situations or locations (such as remot e offices or publicly accessible areas) in which the LAN needs additional protection. When additional protection is needed, Cisco [email protected] Software enables data confidentiality and int egrity on the LAN by using MAC Security (MACsec). Defined by the IEEE 802. 1 AE standard, MACsec secures communication for authorized endpoints on the LAN. Securing the LAN with MACsec Table 1. Typical Termination Mechanisms and Use Cases Use Case Typical Termination Mechanisms unsecure IEEE 802.
IX session MACsec Session All endpoints directly connected Single endpoint per port No IP phones Link down EAPoLLogoff Endpoints connected through IP phone At most two endpoints Cisco Discovery Protocol enhancement for secondport disconnect (Cisco phones) per port (one phone and one data) Proxy EAPoLLogoff message and inactivity timer (phones other than Cisco phones) MKA timeout (phones other than Cisco phones) through hub Physical hub Bridged virtual hubs nactivity timer M KA timeout 1.
Literature review The literature review will providean an overview of the major alternative theories of ne?ork communication in the field of computer arena. The advent Of personal computers (PCs) changed the type Of information sent over office computer networks. Before their rapid spread in the 1970s, employees comm unicated with mainframe and minicomputers by means of socalled “dumb” terminals. All th e processing took place on the main computer that all individuals used simultaneously. Wh en use was heavy, the system’s performance slowed. The PCs took over processing tasks at the desk and thus speeded things up substantially.
With massive computing power no longer ne eded, smaller and simpler “file servers” could be substituted. Computerization thus opened up t o even quite tiny operations. LANs developed simultaneously to connect freestanding computers in offices that, until LANs came, exchanged data by passing diskettes around, and in operations using d umb terminals, such terminals first being replaced by PCs and, later, the connection to mainfr ames severed with the PCs now connected either to each other or to a server; using servers beca me by far the most common LAN configuration.
Developments in LANs proceeded along two fronts in the 1 990s: competing n tworking software systems developed and changes in wiring took place to provide ever faster communications speeds. Wireless transmission appeared in the midl 990s an d had become the leading edge of LAN technology by the mid2000s using a new radiocommunic ations standard known as 802. 1 1, issued by the Institute of Electrical and Electronics Engineer s, Inc.
With the foundation ofWiFi Alliance in 1998 as a certification agency, “WiFi” has come t o mean wireless communications. The abbreviation stands for Wi reless delity. Wireless LANs are referred to as WLANs and sometimes as LAWNS. During the 1 9905, as well, global networking brought about by the explosive development of the Internet has played an enhancing role”enhancing the intimate local aspects of LANs by giving such networks national, indeed international, access too.
LAN technology, in fact, has migrated from businesses to homes. In many residences multiple computers are linked by network connections, some connected bywre and some by radio links.