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Module 11: Network Design - Coggle Diagram
Module 11: Network Design
11.1 Hierarchical Network Design
A hierarchical design divides the network into layers to simplify management and improve performance.
The three main layers are:
Access Layer – connects end devices such as PCs, printers, and IoT devices.
Distribution Layer – aggregates traffic from the access layer and applies policies, routing, and filtering.
Core Layer – provides high-speed backbone connectivity between distribution devices.
Each layer has defined functions that promote modularity, easier troubleshooting, and scalability.
Hierarchical design reduces unnecessary traffic and improves performance by localizing problems.
11.2 Redundancy in a Hierarchical Network
Redundancy ensures continuous network operation in case of device or link failure.
Implemented by adding backup links, switches, or routers between critical points.
First Hop Redundancy Protocols (FHRPs) such as HSRP, VRRP, and GLBP ensure gateway availability.
Redundant paths must be managed carefully to prevent loops, typically using protocols like STP (Spanning Tree Protocol).
Redundancy increases reliability but requires careful configuration to avoid wasted bandwidth or instability.
11.3 Scalability in Network Design
Scalability allows a network to grow without major redesigns.
Hierarchical and modular architectures make adding new devices or services straightforward.
VLANs and subnets help organize and separate network traffic for better control and easier expansion.
Scalable designs anticipate future growth in users, bandwidth, and new technologies such as cloud or IoT.
Good documentation and standardization are key to maintaining scalable network infrastructures.
11.4 Design for Security and Performance
Network design must include security and performance optimization from the beginning.
Security measures include VLAN segmentation, ACLs, firewalls, and secure access control policies.
Performance is improved through load balancing, QoS, and efficient routing protocols.
Proper cabling, port speed, and device placement contribute to both security and performance.
A well-designed network minimizes risks, congestion, and single points of failure.
11.0 Introduction
This module explains how to design networks that are efficient, scalable, and reliable.
It focuses on hierarchical design models, redundancy, scalability, and design considerations for LANs and WANs.
The goal is to ensure that network design supports performance, manageability, and future growth.