This report provides a comprehensive assessment of TCP/IP internetworking, addressing key aspects such as the differences between the OSI and TCP/IP models, hands-on subnetting projects, and the Address Resolution Protocol (ARP). It includes a detailed case study involving the design of a network for an organization expanding its business, dividing the network into six sub-networks, and providing a simple addressing solution. The report justifies the chosen network topology, explains the implications of increasing the number of hosts, and offers subnetting calculations. The /21 routing system is used for IP assignments, with consideration for minimizing wasted IP addresses. The conclusion highlights the efficiency of the designed network architecture while acknowledging the need for redesigning if the number of systems significantly increases.