An approach to solve campus network security problems at three layers of OSI model

With expanding dependence on computer systems all around the world for information storage and data processing, the requirement for legitimate security of data and information cannot be overemphasized. Destruction or revelation of data and unauthorized access can violate people's privacy and threaten the presence of an institution, as information is considered the live wire of an institution. Therefore, it is a necessity to secure the stored information and computer systems. The customary method for securing computer networks, such as software encryption and firewalls are ineffective and insufficient. There is a probability that the network is exposed to harm or physical attack due to its feature of management and monitoring point not being centralized, open medium dynamic changing topology, cooperative algorithms and clear line not well defended. This thesis recognizes many kinds of threats in campus network related to three layers of OSI model (physical, data-link, and network), and proposes several practical solutions from network infrastructure perspective. This study covers three main parts; first, building a campus network with principal security aspects (default configurations). The second part, addressing network's flaws, vulnerabilities and weak points that represent a back door for the network and threaten C.I.A. means (Confidentiality, Integrity and Availability). Moreover, the first important step to know the level of threat is addressing network's flaws. All threats come with three layers will be identified in this study. Also, a solution will be offered for each threat and an example will be given for each solution. Finally, as a part of evaluating the network security, some kinds of attacks will be made (before and after) applying security technologies. The theoretical results of this study represent a reference model for a campus network security through first three layers (P., D., N.) that can be adopted as a good practice to build and secure a robust campus network for the deep information affixed to each part within the three layers. The details will include many recommendations and will be covered at design and implementation of the campus network. The final result in this study gives a bright view about how much we have gained resources and offered more services with guaranteeing information secrecy, service availability, full mean of confidentiality. Decreasing the effect of attacks and increasing the uptime are extra benefits of this study.