Improving Redundant Switched Topologies with EtherChannel透過 EtherChannel 改善備援交換式拓樸

Your company has two data centers in two separate buildings. These buildings are close to each other and connected by a single 10Gbps link. However, as the company has been growing, the link becomes saturated during peak hours, meaning it reaches its maximum capacity and cannot handle additional data traffic efficiently, slowing the network down. To address this, three additional links have been installed between the two buildings. Despite the new connections, the throughput between buildings remains only 10Gbps and not 40Gbps as expected. Could Spanning Tree Protocol (STP) be the reason for this bottleneck?

貴公司在兩棟相鄰的建築物中設有兩座資料中心，兩者透過一條 10Gbps 的鏈路連接。然而，隨著公司規模成長，這條鏈路在尖峰時段已經飽和，也就是達到最大容量，無法有效處理額外的資料流量，導致網路速度變慢。為了解決這個問題，公司在兩棟建築物之間又新增了三條鏈路。儘管新增了這些連線，兩棟建築物之間的吞吐量卻仍然只有 10Gbps，而非預期的 40Gbps。生成樹協定（STP）會不會是造成這個瓶頸的原因？

The figure illustrates that the problem is with STP blocking three out of four links between the two switches to prevent Layer 2 loops. That is why only one 10Gbps link is available.

此圖說明了問題所在：STP 為了防止第 2 層迴圈，阻斷了兩台交換器之間四條鏈路中的三條，因此只有一條 10Gbps 鏈路可用。

You can solve this problem using EtherChannel, which aggregates the four links into a single logical one. This logical link aggregates the four 10Gbps links into one single 40Gbps link. By configuring EtherChannel on your two interconnected switches, you will be able to use all four links simultaneously, preventing packet drops because there will be more available bandwidth.

你可以利用 EtherChannel 來解決這個問題，它會將四條鏈路聚合成一條邏輯鏈路。這條邏輯鏈路把四條 10Gbps 鏈路聚合成單一一條 40Gbps 鏈路。只要在兩台互連的交換器上設定 EtherChannel，你就能同時使用全部四條鏈路，並因為可用頻寬增加而避免封包遺失。

Understanding EtherChannel is very important for a network engineer. Knowing how to use EtherChannel lets you optimize network performance, ensure high availability, and efficiently manage network resources, which are all important skills in today's complex network environments.

了解 EtherChannel 對網路工程師來說非常重要。懂得如何使用 EtherChannel，能讓你最佳化網路效能、確保高可用性，並有效管理網路資源，這些都是在當今複雜網路環境中不可或缺的技能。