Enterprise hierarchical network topology with Palo Alto firewall border security, dual H3C S6520 core switches, and multi-layer VLAN segmentation across DMZ, office, and access tiers. Traffic flows from ISP through the Palo Alto firewall gateway to core switches, then through H3C L3 aggregation switches to L2 access switches serving office PCs and wireless APs. This three-tier design provides redundancy, scalability, and security segmentation across VLANs 10, 20, 30, and 100-130. Network architects can fork this diagram to customize VLAN assignments, add additional aggregation layers, or integrate OCI network services like Virtual Cloud Networks and Network Security Groups. The architecture demonstrates best practices for enterprise network resilience through dual core switch interconnection and load distribution across aggregation tiers.