Enterprise network architecture spanning firewall perimeter through access layer using Palo Alto PA-3200, H3C core switches, and multi-tier aggregation. ISP broadband WAN connects through the Palo Alto firewall to DMZ servers (Web 172.16.10.10, Database 172.16.10.20) and redundant H3C S6520-X core switches. Dual aggregation layers (Agg-SW-01, Agg-SW-02) distribute traffic to four access switches serving PCs and wireless APs. This architecture demonstrates defense-in-depth with clear trust boundaries, redundancy at core and aggregation tiers, and scalable access layer design. Fork this diagram on Diagrams.so to customize VLAN assignments, add additional access switches, or integrate OCI networking services. The dual-core design ensures high availability while the DMZ isolation protects internal resources from internet-facing threats.