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Cidr Calc

接收单个 CIDR 字符串并校验格式,使用标准子网公式计算网络地址、广播地址、子网掩码、通配符掩码、可用主机范围、主机数量、IP 类别、网络类型和二进制表示,并按带标签的文本格式输出结果。

ohernandez-dev-blossom
ohernandez-dev-blossom
热度 44.64
最近更新 2026-05-11 17:35:19
分类:效率依赖:纯提示词应用场景:数据处理

安装技能

复制下面的话术发给你的 Agent,它会通过 secure-skills 检索并安装该技能。

执行命令安装此 skill: npx secure-skills-cli add cidr-calc
Metadata
name
cidr-calc
description
Calculate subnet information from CIDR notation. Use when the user asks to calculate a subnet, find the network address, broadcast address, host range, subnet mask, or number of hosts for an IP in CIDR notation like 192.168.1.0/24.

CIDR Calculator

Given an IP address in CIDR notation, compute all subnet parameters: network address, broadcast, host range, subnet mask, wildcard mask, host counts, IP class, and binary representation.

Input

  • A CIDR notation string in the format A.B.C.D/N (e.g. 192.168.1.0/24)

Output

A structured result with these fields:

  • CIDR Notation (normalized)
  • Network Address
  • Broadcast Address
  • Subnet Mask
  • Wildcard Mask
  • First Usable Host
  • Last Usable Host
  • Total Hosts (2^(32-N))
  • Usable Hosts
  • IP Class (A / B / C / D Multicast / E Reserved)
  • Network Type (Private / Public)
  • Binary Representation of the IP

Instructions

  1. Validate the input. It must match \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\/\d{1,2}. Each octet must be 0–255. Prefix must be 0–32.
  2. Compute values using standard subnet math:
    • maskNum = (0xFFFFFFFF << (32 - prefix)) >>> 0
    • wildcardNum = ~maskNum >>> 0
    • networkNum = (ipNum & maskNum) >>> 0
    • broadcastNum = (networkNum | wildcardNum) >>> 0
    • totalHosts = 2^(32 - prefix)
    • usableHosts: if prefix == 32 → 1; if prefix == 31 → 2; else totalHosts - 2
  3. Determine IP class from first octet:
    • 1–126 → A; 128–191 → B; 192–223 → C; 224–239 → D (Multicast); 240–255 → E (Reserved); 127 → Loopback
  4. Determine private vs public:
    • Private: 10.x.x.x, 172.16–31.x.x, 192.168.x.x, 127.x.x.x (loopback)
  5. Compute binary as four 8-bit groups joined by dots.
  6. Present results in a clear labeled format.

Quick CIDR reference

CIDR Subnet Mask Total Hosts
/8 255.0.0.0 16,777,216
/16 255.255.0.0 65,536
/20 255.255.240.0 4,096
/22 255.255.252.0 1,024
/24 255.255.255.0 256
/28 255.255.255.240 16
/30 255.255.255.252 4
/32 255.255.255.255 1

Options

  • Input is always a single CIDR string; no additional options.

Examples

Input: 192.168.1.0/24

Output:

CIDR Notation:   192.168.1.0/24
Network Address: 192.168.1.0
Broadcast:       192.168.1.255
Subnet Mask:     255.255.255.0
Wildcard Mask:   0.0.0.255
First Host:      192.168.1.1
Last Host:       192.168.1.254
Total Hosts:     256
Usable Hosts:    254
IP Class:        C
Network Type:    Private
Binary:          11000000.10101000.00000001.00000000

Input: 10.0.0.0/8

Output:

CIDR Notation:   10.0.0.0/8
Network Address: 10.0.0.0
Broadcast:       10.255.255.255
Subnet Mask:     255.0.0.0
Wildcard Mask:   0.255.255.255
First Host:      10.0.0.1
Last Host:       10.255.255.254
Total Hosts:     16,777,216
Usable Hosts:    16,777,214
IP Class:        A
Network Type:    Private
Binary:          00001010.00000000.00000000.00000000

Error Handling

  • If the input is not valid CIDR notation, say so and provide the expected format (A.B.C.D/N).
  • If an octet exceeds 255 or the prefix exceeds 32, explain the validation error.
  • If the user provides an IP without a prefix (e.g. 192.168.1.1), ask for the prefix length or assume /32.