Central Switch and Access Switches

Access switches connect end-user devices to the network, while central (core) switches form the high-speed backbone that interconnects distribution and access layers.Access Switches

Access switches operate at the network edge, directly connecting end-user devices such as computers, IP phones, wireless access points, cameras, and IoT devices to the network . They are typically located in the access layer of a hierarchical network and provide:

• High port density to accommodate multiple devices .
• Power over Ethernet (PoE) for devices like IP phones and cameras .
• VLAN support and local traffic forwarding, enabling efficient communication within subnets .
• Security features such as port security, DHCP snooping, and MAC address filtering . Access switches are often Layer 3 capable, meaning they can perform routing between VLANs or subnets, but their primary role is to provide network access to end devices and forward traffic upstream to distribution or core switches .

Central (Core) Switches

Central switches, also called core switches, operate at the top layer of a hierarchical network and form the backbone that interconnects distribution switches and, indirectly, access switches . Their key characteristics include:

• High-speed data forwarding to handle large volumes of traffic with minimal latency .
• Scalability and fault tolerance, often using multiple core switches to prevent congestion and ensure network reliability .
• Centralized routing and switching, supporting advanced features like inter-VLAN routing, policy enforcement, and integration with security appliances . Core switches are critical for network performance, as the efficiency of the entire network depends on their ability to route and switch traffic between distribution and access layers .

Hierarchical Network Context

In a three-tier network model:

1. Access Layer: Access switches connect end devices and handle local traffic.
2. Distribution Layer: Distribution switches aggregate traffic from multiple access switches, enforce policies, and provide redundancy.
3. Core Layer: Central/core switches form the high-speed backbone, connecting distribution switches and ensuring fast, reliable data transfer across the network . This hierarchy improves network manageability, scalability, and performance, compared to flat networks where all devices connect to a single switch.

Summary

• Access switches: Edge devices, connect end-users, provide PoE, VLANs, and security at the subnet level.
• Central/core switches: Backbone devices, high-speed, aggregate distribution traffic, ensure network reliability and low latency.
• Together, they form a structured, hierarchical network that balances performance, security, and manageability .