Three-Branch Hub-and-Spoke WAN (Cisco)

Hub-and-spoke WAN topology connecting three branch offices to a central HQ across a simulated internet backbone. Hierarchical IP addressing (172.23.0.0/16), RIPv2 routing with PPP authentication, DHCP per branch, and standard plus extended ACL policies controlling inter-branch and internet-facing traffic.

Built as a Singapore Polytechnic networking lab. The full topology lived only in Cisco Packet Tracer's Multi-User Mode, with no physical hardware involved. That made it straightforward to spin up failure scenarios and verify the routing converged the way the design intended.