IPv4 CIDR parse

ipv4-cidr-parse · version 1.0.0 · URLs & IP addresses · free, no key needed

Parse an IPv4 CIDR block into its network, broadcast, netmask, wildcard mask, usable host range and address counts.

Use when you need to: ipv4 cidr parse · ipv4 subnet info · ipv4 cidr to network details.

Supported

• ipv4 cidr parse
• ipv4 subnet info
• ipv4 cidr to network details

Not supported

• IPv6
• host-address CIDR notation (host bits must be zero)
• dotted netmask input

Behavior

• cidr is dotted-decimal/prefix with prefix a canonical decimal integer 0-32 and no leading zeros except 0.
• The network address must have host bits zero; otherwise the tool throws "cidr host bits must be zero".
• total_count is the canonical decimal string 2^(32-prefix), the size of the block including network and broadcast.
• usable_host_count follows RFC 3021: /32 has 1 usable host (itself), /31 has 2 (both addresses, no reserved network/broadcast), /0-/30 reserve the first address as network and the last as broadcast.
• first_usable_host/last_usable_host equal network/broadcast for /31 and /32.

Input

• cidr (string, required): max length 18

Output

• network (string, required): max length 15
• broadcast (string, required): max length 15
• netmask (string, required): max length 15
• wildcard_mask (string, required): max length 15
• prefix (integer, required): min 0; max 32
• first_usable_host (string, required): max length 15
• last_usable_host (string, required): max length 15
• usable_host_count (string, required): pattern ^(0|[1-9][0-9]*)$
• total_count (string, required): pattern ^(0|[1-9][0-9]*)$

Limits

• max cidr length: 18
• prefix min: 0
• prefix max: 32

Example

Request input:

{
  "cidr": "192.168.1.0/24"
}

Response:

{
  "result": {
    "network": "192.168.1.0",
    "broadcast": "192.168.1.255",
    "netmask": "255.255.255.0",
    "wildcard_mask": "0.0.0.255",
    "prefix": 24,
    "first_usable_host": "192.168.1.1",
    "last_usable_host": "192.168.1.254",
    "usable_host_count": "254",
    "total_count": "256"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "ipv4-cidr-parse",
  "version": "1.0.0",
  "input": {
    "cidr": "192.168.1.0/24"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/ipv4-cidr-parse/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"cidr":"192.168.1.0/24"}'

The machine-readable contract is at /v1/tools/ipv4-cidr-parse/versions/1.0.0.

CLI

node cli.mjs run ipv4-cidr-parse 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• IPv6 CIDR parse: Parse an IPv6 CIDR block into its canonical network address, prefix, first/last address, and total address count.
• IPv4 CIDR contains: Test whether one IPv4 CIDR block fully contains another IPv4 CIDR block.
• IPv4 CIDR overlap: Test whether two IPv4 CIDR blocks overlap (share at least one address).
• IPv4 in CIDR: Test whether a canonical IPv4 address lies in a CIDR prefix whose host bits are zero.
• IPv4 mask convert: Convert between an IPv4 prefix length, dotted subnet netmask, and dotted wildcard (host) mask.
• IPv4 parse: Parse a canonical dotted-decimal IPv4 address into octets and a uint32 integer string.