Introduction
簡介
Imagine you are a network engineer at a growing tech company that is expanding rapidly. The company has recently expanded its operations and acquired additional office space to accommodate 50 new employees across various departments. You have been tasked with redesigning the enterprise network to meet the increasing demands of the business and to integrate new users.
假設您是一家快速成長的科技公司的網路工程師。該公司最近擴大營運，並新增了辦公空間以容納各部門新增的 50 名員工。您被指派重新設計企業網路，以滿足業務日益成長的需求並整合新使用者。
Since nobody expected the company to expand so quickly, the network is not structured for this many users. For the first time, you are faced with the challenges of a poorly designed network with no proper, thought-out design, such as:
由於沒有人預期公司會如此快速擴張，網路架構並未針對這麼多使用者進行規劃。您首次面臨網路設計不良、缺乏周全規劃的挑戰，例如：
- Scalability issues: The network infrastructure is not scalable enough to adapt to the changing needs.可擴充性問題：網路基礎架構的可擴充性不足，無法因應不斷變化的需求。
- Performance bottlenecks:The network is struggling to cope with peak usage times, resulting in slow performance for critical applications.效能瓶頸：網路難以應付尖峰使用時段，導致關鍵應用程式效能低落。
- Security concerns: The lack of proper network segmentation exposes sensitive data and increases the risk of security breaches.安全性疑慮：缺乏適當的網路區隔，使敏感資料暴露在外，增加安全性遭入侵的風險。
- Redundancy issues:The lack of redundant connections leads to singe points of failure throughout the network.備援問題：缺乏備援連線，導致整個網路出現單點故障。
- Failure domains: The network has far-reaching failure domains, meaning that issues in one part of the network can affect the entire system.故障網域：網路的故障網域範圍過廣，代表網路某一部分發生問題可能影響整個系統。
Because the network was not designed with scalability in mind, the problem gets worse with each additional new user. In the figure, traffic from the new office travels across the engineering switch to reach the internet, causing performance issues for both sets of users.
由於網路在設計時並未考量可擴充性，隨著每新增一名使用者，問題就會愈加嚴重。如圖所示，來自新辦公室的流量須經過工程部門的交換器才能連上網際網路，導致兩批使用者的效能都受到影響。
Even with an improved network architecture, the cost of additional hardware may be too high, requiring you to find ways to optimize the resources.
即使改善了網路架構，額外硬體的成本可能仍過高，因此您需要設法最佳化資源運用。
 | How will you design the network and optimize the use of the resources? 您會如何設計網路並最佳化資源運用？ |
As a network engineer, you need to address these issues by considering different architecture models to determine the best fit for your company's needs. You will also need to explore virtualization to create virtual devices and optimize the use of physical resources. Additionally, you may need to understand cloud basics to integrate cloud services into your network.
身為網路工程師，您需要考量不同的架構模型，找出最適合公司需求的方案，藉此解決這些問題。您也需要探索虛擬化，以建立虛擬裝置並最佳化實體資源的運用。此外，您可能還需要了解雲端基礎知識，以便將雲端服務整合到您的網路中。
Luckily, you can also use tools like Cisco Modeling Labs which leverage virtualization to provide test network environments where you can compare different options and try out the what-if scenarios.
幸運的是，您也可以使用 Cisco Modeling Labs 之類的工具，利用虛擬化技術提供測試網路環境，讓您比較不同方案並嘗試各種假設情境。
Using a more scalable architecture, you can easily add new switches without affecting the existing links. Additionally, you can optimize resource usage by virtualizing some network devices and services.
採用更具擴充性的架構，您可以輕鬆新增交換器而不影響現有連線。此外，您還可以透過將部分網路裝置與服務虛擬化來最佳化資源使用。
In this course, you will learn about the following:
在本課程中，您將學習以下內容：
- Network architecture models:Describe typical network architectures, including the enterprise hierarchical model and spine-leaf network design.網路架構模型：說明典型的網路架構，包括企業階層式模型與 spine-leaf 網路設計。
- Virtualization fundamentals: Explore basic virtualization concepts (server virtualization, containers, virtual routing and forwarding (VRFs)).虛擬化基礎：探討虛擬化的基本概念（伺服器虛擬化、容器、虛擬路由與轉送（VRF））。
- Cloud computing basics: Discover cloud services to optimize network scalability and performance.雲端運算基礎：了解可最佳化網路可擴充性與效能的雲端服務。
- Cisco Modeling Labs: Explore Cisco Modeling Labs basics and how CML can help with different network engineering tasks.Cisco Modeling Labs：探討 Cisco Modeling Labs 的基本概念，以及 CML 如何協助各種網路工程任務。