什麼是 CIDR？

一個 IP 地址由兩個部分組成：

An IP address is made up of two parts:

• 網路地址是指向網路唯一識別符的一串數字 
• 主機地址是一系列數字，用於表示網路上的主機或單個裝置的識別符

直到 1990 年代初，IP 地址都是使用分級式定址網路系統分配的。地址的總長度是固定的，分配給網路和主機部分的位元數也是固定的。

Until the early 1990s, IP addresses were distributed using a hierarchical address network system. The total length of the address is fixed and the number of bits assigned to the network and host parts is fixed.

一個 IPv4 地址由 32 個位元組成。每串數字由 8 個位元組成，可為 0 到 255，各串數字之間由句點分隔。組織可以購買三類 IPv4 地址。 

An IPv4 address is made up of 32 bytes. Each string is composed of 8 bytes, which can be separated between 0 and 255 numbers. Organizations can buy three types of IPv4 addresses. & nbsp;

A 類

A 類 IPv4 地址有 8 個網路字首位。以 44.0.0.1 為例，其中 44 是網路地址，0.0.1 是主機地址。

An A-type IPv4 address has the first eight network words. Take 44.0.0.1, for example, 44 is a network address and 0.01 is a host address.

B 類

B 類 IPv4 地址有 16 個網路字首位元。以 128.16.0.2 為例，其中 128.16 是網路地址，0.2 是主機地址。

The B-type IPv4 address has 16 first characters. For example, 128.16.0.2, of which 128.16 is the Internet address and 0.2 is the host address.

C 類

C 類 IPv4 地址有 24 個網路字首位元。以 192.168.1.100 為例，其中 192.168.1 是網路地址，100 是主機地址。 

Type C IPv4 addresses have 24 first characters. For example, 192.168.1.100, of which 192.168.1 is a web address and 100 is a host address. & nbsp;

無類別或無類別域間路由 (CIDR) 地址使用可變長子網路遮罩 (VLSM) 來改變 IP 地址中網路地址位和主機地址位之間的比率。子網路遮罩是一組識別符，透過將主機地址變為零，從 IP 地址傳回網路地址的值。 

Unique or Unique Area Route (CIDR) addresses change the ratio between the Internet address and the host address in an IP address by using a variable long-son network mask (VLSM). The sub-network mask is a set of identifiers that returns the value of the Internet address from an IP address by changing the host address to zero. & nbsp;

VLSM 序列允許網路管理員將 IP 地址空間分解為不同大小的子網路。每個子網路都可以有靈活的主機數和有限數量的 IP 地址。一個 CIDR IP 地址由普通 IP 地址和字尾組成，該字尾用於說明網路地址字首位元數。

The VLSM sequence allows network managers to divide IP addresses into sub-networks of different sizes. Each sub-network has a live host number and a limited number of IP addresses. A CIDR IP address is composed of a normal IP address and a wordtail, which is used at the end to describe the first character of the network address.

例如，192.0.2.0/24 是一個 IPv4 CIDR 地址，其中前 24 位或 192.0.2 為網路地址。 

For example, 192.2.0/24 is an IPv4 CIDR address, of which the first 24 places or 192.02 are Internet addresses. & nbsp;

藉助無類別域間路由 (CIDR)，我們可以更靈活地在裝置之間指派 IP 地址和路由資料。

With the help of CIDR, we can assign IP addresses and route data more vividly between devices.

CIDR 可以讓我們靈活地指派 IP 地址的網路和主機識別符。您可以使用 CIDR 為特定網路提供所需數量的 IP 地址並減少浪費。此外，CIDR 減少了路由表項目，簡化了封包路由。 

CIDR allows us to assign IP addresses to networks and host identifiers. You can use CIDR to provide the required number of IP addresses for a given network and to reduce the cost. In addition, the CIDR has reduced the route list items and simplified the package route. & nbsp;

CIDR 允許路由器更有效地將 IP 地址整理到多個子網路中。一個子網路是存在於一個網路中的較小網路。例如，連線至路由器的所有裝置都在同一個子網路中，並具有相同的 IP 地址字首。

CIDR allows routers to organize IP addresses more effectively in multiple sub-networks. A sub-network is a smaller network in a network. For example, all devices connected to routers are in the same sub-network and have the same IP address header.

我們可以使用 CIDR 建立和整合多個子網路。這使資料無需走不必要的路徑，便可更快到達目的地地址。 

We can use the CIDR to create and integrate multiple sub-networks. This makes it easier for data to reach their destination address without having to follow an unnecessary path. & nbsp;

虛擬私有雲端 (VPC) 是託管在雲端中的私有數位空間。其允許我們在隔離且安全的環境中佈建工作負載。VPC 在連線的裝置之間傳輸封包時使用 CIDR IP 地址。 

Virtual private cloud (VPC) is a private digital space in the cloud. It allows us to load work in isolated and secure environments. VPC uses the CIDR IP address when transferring a package between connected devices. & nbsp;

超網是具有相似網路字首之子網路的群組。我們可以使用 CIDR 靈活地建立超網，而這在傳統的遮罩架構中是不可能的。例如，我們可以使用如下標記法將 IP 地址組合到一個網路地址區塊中：

Hypernet is a group of children with a similar network header. We can use the CIDR to create the supernet, which is not possible in traditional mask structures. For example, we can use the following tags to group IP addresses into a network address block:

• 192.168.1 /23 
• 192.168.0 /23

此標記法將子網路遮罩 255.255.254.0 套用於 IP 地址，從而傳回前 23 個位元作為網路地址。路由器只需要透過一個路由表便可以管理子網路上裝置之間的封包傳輸。

This label applies the subnet mask 255.255.254.0 to the IP address, from which it returns 23 bits of the previous address as a network address. A router can manage a package transfer between devices on the sub-network only by means of a route watch.

IPv6 是一種旨在取代 IPv4 的聯網定址系統。IPv6 使用 128 位唯一識別符，可容納的 IP 地址數量是 IPv4 的 1,028 倍。

IPv6 is a network address system designed to replace IPv4. IPv6 uses 128 bits of unique identifiers, and the number of IP addresses available is 1,028 times that of IPv4.

IPv6 地址由 8 個以冒號分隔的十六進位值組成。IPv6 的地址空間要大得多，能夠應對當今連線至網際網路的裝置越來越多的狀況。

IPv6 addresses are composed of eight colon-separated hexadecimals. The IPv6 addresses have much larger space to cope with the increasing number of devices that are now connected to the Internet.

在使用無類別域間路由 (CIDR) 時，IPv6 地址可以與任意位元長度的字首組合，類似於 IPv4 地址。例如，2001:0db8:/32 是一個 IPv6 CIDR 地址，前 32 位 (即 2001:db8) 是網路地址。 

When using the Unique Area Route (CIDR), the IPv6 address can be combined with the first words of any bit length, similar to the IPv4 address. For example: 2001:0db8:32 is an IPv6 CIDR address, the first 32 (i. e. 2001:db8) is an Internet address. & nbsp;