計算機網絡子網劃分

1)子網劃分 (1) Subnetting)

Subnetting is a concept of diving a block of addresses into sub-blocks of addresses. During the era of classful addressing (as it’s obscured now), subnetting was introduced. Say, an organization is granted a large block in class A or B, it can divide the address block assigned into several contiguous groups (sub-blocks) and assign each group to smaller networks (subnets).

子網劃分是將地址塊分成地址子塊的概念。 在分類尋址時代(現在已經模糊)，引入了子網劃分。 假設組織被授予A或B類中的一個大塊，它可以將分配的地址塊劃分為幾個連續的組(子塊)，并將每個組分配給較小的網絡(子網)。

2)超網 (2) Supernetting)

The biggest drawback of classful addressing is address depletion. The issue came in front when most of class A and class B addresses were depleted and there was still a huge demand for midsize blocks. Class C was too small to adjust and solve the situation as the size of a class C block with a maximum number of 256 addresses hardly satisfied the needs of most organizations.

分類尋址的最大缺點是地址耗盡。 當大多數A類和B類地址用盡并且對中型塊的需求仍然很大時，問題就擺在了前面。 C類太小，無法調整和解決這種情況，因為具有最多256個地址的C類塊的大小很難滿足大多數組織的需求。

Even a midsize organization needed more address range. The solution was supernetting.

即使是中型組織也需要更大的地址范圍。 解決方案是超網。

In supernetting, an organization can combine several class C blocks to create a larger block of addresses. Several networks were combined to create a supernetwork. An organization can apply for a set of class C blocks (i.e. multiple class of C blocks) instead of just one. For example, an organization that needs 500 addresses can be granted three contiguous class C blocks. Then, an organization can use such addresses to create one supernetwork.

在超網中，組織可以組合多個C類塊來創建更大的地址塊。 幾個網絡被合并以創建一個超級網絡。 一個組織可以申請一組C類塊(即多個C類塊)，而不是一個。 例如，一個需要500個地址的組織可以被授予三個連續的C類塊。 然后，組織可以使用此類地址創建一個超級網絡。

Classless addressing actually eliminated the need for supernetting.

實際上，無類尋址消除了對超網的需要。

翻譯自: https://www.includehelp.com/computer-networks/subnetting-and-supernetting.aspx

計算機網絡子網劃分