<![CDATA[The increasing dependence of government institutions on internet-based services has made network security a strategic requirement for preserving data confidentiality, service availability, and public trust. This study evaluates the reliability and mitigation effectiveness of MikroTik firewall rules in securing the internet network of a local government institution against three attack scenarios: packet sniffing, port scanning, and Distributed Denial of Service (DDoS). An experimental design was employed to compare network conditions before and after the activation of firewall rules. ARP spoofing-based packet sniffing was simulated using Ettercap, port scanning was performed using Zenmap, and DDoS traffic was generated using Hping3. In contrast, Wireshark and Winbox were used to monitor network traffic and firewall responses. The initial results show that before firewall activation, the network was exposed to multidimensional risks: packet sniffing revealed DHCP packets and IP-MAC metadata, port scanning identified 8 open ports, and the DDoS attack increased CPU utilization to 100% and elevated memory usage. After the firewall rules were activated, all three attacks were successfully mitigated. Sniffing activity was limited to normal DHCP Discover traffic, port scanning no longer revealed open ports, and DDoS packets were dropped before establishing effective connections. Overall, the MikroTik firewall achieved 100% reliability within the tested scenarios, demonstrating its effectiveness in reducing traffic exposure, controlling service visibility, and maintaining system availability in a government network environment.]]>
