The core router is located below the switch

In a hierarchical network, a core router is typically positioned at the core layer, often connected to core switches, rather than physically “below” them; placement depends on logical network design rather than physical stacking.Understanding Core Routers and Core SwitchesA core router is designed to operate at the backbone of a network, handling high-speed IP packet forwarding and supporting multiple high-capacity interfaces for large-scale traffic management . It is distinct from edge routers, which connect external networks to the core . Core routers are optimized for routing between different network segments and often form the central hub for WAN connectivity. A core switch, on the other hand, is a high-capacity Layer 3 switch that aggregates traffic from distribution switches and provides ultra-low latency switching within the LAN . It acts as the backbone of the local network, ensuring rapid data transfer across the enterprise infrastructure.Placement ConsiderationsLogical Hierarchy: In a three-tier network model, the core layer sits at the top, connecting distribution switches and providing high-speed paths to routers and data centers . Core routers are typically connected to core switches to route traffic between VLANs, subnets, or external networks .Physical Layout: The physical placement “below” a switch may refer to rack positioning, but this does not affect the logical hierarchy. Core routers can be mounted in the same rack as core switches or in adjacent racks, depending on space, cooling, and cabling considerations .Redundancy: Best practices often include dual core switches and redundant connections to core routers to prevent single points of failure . Each floor or distribution switch may connect via fiber to the core switches, which then interface with the core router for WAN or inter-VLAN routing.Key TakeawaysCore routers and core switches serve complementary roles: routers handle inter-network traffic, while switches handle high-speed intra-network traffic.Physical placement in a rack does not dictate network hierarchy; the logical connections define the core layer.Redundant connections and proper cabling ensure high availability and performance in enterprise networks . In summary, while a core router may be physically located below a switch in a rack, it remains part of the core layer and is logically connected to core switches to manage routing and backbone traffic efficiently.