3.1 Core/Spine Layer (GX or Equivalent): • GX-class spine/core switches (Cisco Nexus 9300-GX series or equivalent) • Non-blocking architecture with minimum 2–4 Tbps switching capacity per chassis • 400G, 100G, and 40G port support (QSFP-DD, QSFP28) • High-density uplinks to leaves with ECMP support for resiliency and load balancing • VXLAN EVPN support for scalable Layer 2/3 fabric • Segment Routing (SR/SRv6) capability for advanced traffic engineering • Advanced L2/L3 features including OSPF, BGP, IS-IS, and MPLS • Hot-swappable, redundant power supplies and fans 3.2 Leaf Layer (FX or Equivalent): • FX-class leaf switches (Cisco Nexus 9300-FX3 series or equivalent) • High-density 10/25/40/100GbE ports (SFP+/QSFP+/QSFP28) for server and user aggregation • Support for 1G/10G copper (RJ-45) where legacy or management connections are required • VXLAN EVPN leaf functionality with distributed anycast gateway • MACsec encryption supported at line rate on all ports • PTP/SyncE boundary clock functionality for time-sensitive applications • Spine-leaf compatibility for modular growth 3.3 Fabric Features & Capabilities: • Leaf–spine topology with dual-homed leaves and redundant spines • Scalability to support migration toward 400G fabrics • Logical segmentation via VRFs (NX-OS) or Tenants/EPGs (ACI) • Firewall and MPLS edge integration with 100G WAN/MPLS handoff • eBGP or OSPF routing with strict policy control • Firewalls dual-homed to the fabric with per-VRF/tenant separation • Advanced QoS with prioritization for voice, video, and critical application data • Security: ACLs, RBAC, MACsec, and microsegmentation • Dual-stack IPv4/IPv6 compliance
