Febriansyah Febriansyah
The development of a company's operational needs requires a more structured, efficient, and adaptive computer network infrastructure that can support organizational growth. The expansion of the office from one shophouse unit into two shophouse units increases the need for wireline and wireless networks capable of supporting user connectivity, work devices, internet access, and supporting devices such as CCTV. This research aims to design a wireline and wireless network that supports the development of office infrastructure using the Network Development Life Cycle (NDLC) method. The proposed design includes network topology planning, structured IP addressing, network segmentation using Virtual Local Area Network (VLAN), guest network access restriction, and multi-ISP connectivity through failover and failback mechanisms. The network simulation was carried out using GNS3 with MikroTik CHR as the main device to perform routing, VLAN, DHCP, NAT, firewall, and failover functions. The test results show that each client can obtain an IP address according to its respective VLAN, connect to the gateway, and access the internet. VLAN segmentation successfully separates the network based on its functions, namely Admin, Operational, CCTV, and Guest WiFi. Firewall testing shows that the Guest network can still access the internet but cannot access the internal network. In addition, the failover and failback mechanisms successfully operate when the primary ISP link is disabled and re-enabled. Thus, the proposed network design is able to represent the needs of office infrastructure development in a more structured manner and in accordance with the research objectives.