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CIDR 计算器

子网掩码, IP 范围 calculation and network planning tool

IP地址
子网划分
Common CIDRs
CIDR Calculation 结果

Enter IP地址 and prefix length to 开始 calculation

CIDR Knowledge

What is CIDR?

CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and performing IP routing. It uses prefix length to represent the 大小 of the network portion, replacing traditional A, B, C class network divisions.

子网掩码

子网掩码 is used to distinguish the network portion and host portion in an IP地址. The shorter the prefix length, the larger the network and more hosts; the longer the prefix length, the smaller the network and fewer hosts.

子网划分

子网划分 is the process of dividing a large network into multiple smaller sub-networks, which can improve network security, reduce broadcast domains, and optimize network performance. Consider actual requirements when dividing subnets.

Private IP Addresses

Private IP addresses include: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16. These addresses can only be used within internal networks and cannot be directly routed on the Internet.