Abstract: This study was conducted using the Local Area Network (LAN) of the Niger mills, Calabar, Cross River state, Nigeria. It entailed the simulation of LAN with a view to checking its quality, latency and also creating a firewall security device to mitigate the rate of cybercrime. A simulator-software (Packet tracer) was used to design, configure, troubleshoot and visualize network traffics within a controlled simulated program environment. The various components of the network were configured using commands and CISCO 3600 router. The design was also made up of 3 core layer switches with 24 ports each, and 44 computer systems connected to them. Other key items were: hubs, repeaters and two servers that served as system backups. Various computer systems were configured using the Class C IP addressing system. The packets captured on the Niger mills network were analyzed based on the application protocol and the transport protocol. From the study, it was observed that web browsing (HTTP) constituted the highest traffic with 42.9%. This was followed closely by SMPT/POP with 28.9% and the FTP with 16.39%. Others were the DNS with 10.41% and SMB with 1.3%. Further findings indicated that the created firewall into the LAN network was able to prevent intruders and screened unauthorized users from accessing the system. In addition, firewall was able to filter incoming network traffic based on source or destination, filter outgoing network traffic based on source or destination, filter network based on content, detect and filter mal ware, make internal resource available, report on network traffic and firewall activities. This is in line with what Hooke assertions when he conducted a similar simulation using firewall to check the rate of cyber crime in a WAN. Traffic activities of the network were monitored and reported. In order to ensure routine system checkup and to further curb the problem of latency, a qualified network administrator should be hired to manage the network. Further studies should be carried out using a more sophisticated software application (OPNET) in simulating the different networks (LAN, MAN, WAN).