Overview
This lecture introduces various network topologies, explains their structures, and discusses their uses in enterprise network design and troubleshooting.
Common Network Topologies
- A network topology defines how devices are physically or logically connected.
- Understanding topologies aids in planning and troubleshooting network connections.
Star (Hub and Spoke) Topology
- Star topology uses a central device (usually a switch) to connect all other network devices.
- All communication between devices passes through the central hub.
- Switched Ethernet is a common example of the star topology.
Mesh Topology
- Mesh topology connects devices with multiple links for redundancy and alternate paths.
- Supports load balancing by distributing data across different paths.
- Commonly used in wide area networks (WANs) for reliable remote site connectivity.
Hybrid Topology
- Hybrid topology combines multiple types such as star, mesh, and point-to-point within a single network.
- Used in large enterprise networks to optimize performance and reliability.
Spine and Leaf Architecture
- Spine and leaf uses spine switches at the top and leaf switches in the middle, with devices connecting to leaves.
- Spines connect to all leaves, but leaves and spines do not connect directly to each other.
- Ideal for data centers, especially with top-of-rack switching for simplified cabling and redundancy.
- Every rack in the data center gets its own leaf switch, increasing cost with more racks.
Point-to-Point Topology
- Point-to-point topology directly connects two network endpoints.
- Used in older WAN designs (e.g., T1 or T3 lines) and connecting campus buildings.
Key Terms & Definitions
- Network Topology — The arrangement of various elements (links, nodes) in a computer network.
- Star Topology — All devices connect to a central device, forming a hub-and-spoke pattern.
- Mesh Topology — Devices are interconnected, providing multiple paths for data.
- Hybrid Topology — Combination of two or more different types of network topologies.
- Spine and Leaf — Data center architecture with interconnected spines (core) and leaves (access) switches.
- Point-to-Point — A direct link between two networking devices.
Action Items / Next Steps
- Review examples of each topology in your textbook or course material.
- Practice sketching network diagrams for each topology.
- Prepare questions about topologies for the next lecture.