Abstract: The current scenario in the communication domain is mainly focused on internet. Therefore, for a secured and reliable communication arises a need to design a structure that translates business requirements into technical specifications. This paper mainly focuses on the current security issues such as DHCP spoofing, MAC flooding, VLAN attacks, etc. Security is integral part of any type of network. Without a full understanding of the threats that are involved, network security mechanism tends to be incorrectly configured. This motivates to design a proposed system that aims at building an organized infrastructure that is the Three Tier Architecture with enhanced security at layer 2 and layer 3. Proposed framework focuses that Security is an infrastructure service that increases the integrity of the networks by protecting network resources and users from external and internal attacks. Projected architecture is deployed using software tool GNS3 a combination of virtual and real devices, used to simulate complex networks.

Keywords: Three Tier Architecture, DHCP, MAC, VLAN, Port security.