IntroductionThe ubiquitous nature of computer network connectivity may aid computer users into accessing the world, while at the same time it may enable the same world to access those same computer systems in an undesirable manner. It is this unique nature of computer networking that becomes of prime concern for our information systems and data security. Regardless of the security of our hosts, information systems are, and will continue to be vulnerable if parts of the infrastructure between our distant destinations and ourselves become victims to security exploitation. Also going by the fact that, information security and data exchange are inextricable linked, modern computer networking engineers have to be security conscious while at the same time they have to understand the network that they are mandated to secure (E Cole et al.
2003). It is this particular scenario that has made security, between sites, system, and applications, a major consideration and expense for any modern organization. OSI LayersThe Open Systems Interconnect (OSI) layers, enables the network engineers, to understand data communications between any two networked computer systems by dividing the communication systems into seven different layers in which each layer has been mandated to specific functions to either support the layer above or below it. FIG 1.0 Depiction of OSI layersLayer 1 the physical LayerThis is the layer that defines the connectors and interface applications together with the medium used (cables).
It involves all the electrical, mechanical, and procedural specifications that are provided for sending bit streams through the computer systems network, and some of the components used in this layer may include; Cabling systems, Adapters that connect to physical interfaces, Hubs & repeaters, wireless devices, network interface cards among others (Paul Simoneau, 2006). This layer is the most critical when it comes to data security and denial of service may be launched by a mere circuit breaking or just unplugging the power cord or network cable.
Other security vulnerabilities may include loss of power, physical theft of data and computer hardware, undetected interception of data, key stroking and other input login. (Damon Reed, 2003). However, this security situation may be contained by, locked enclosures, video & audio surveillance, biometric authentication and cryptography techniques among others. Layer 2- Data link LayerThis particular layer mainly allows devices to access the network, send and receive messages, it also offers physical address to devices that are present on the network so that the devices’ data present on the network can be sent.
It also synchronizes with the devices networking software seamlessly in order to send and receive messages and it may also proceed and provide error detection capability (Paul Simoneau, 2006)Some of the common components in this layer include, network interface cards, Ethernet & token rings, Bridges e. t.c This layer is also the realm of wireless protocols such as the 802.11 wireless networking and it is due to this wireless capability that signals may go beyond the intended range to the outside public, whereby some wireless access point, may lack sufficient control at this particular layer, hence letting anyone with signals at the physical layer to easily interconnect to the network