CIDR::/slicer 🔪🍎

Zero-dependency lib for manipulating IP Addresses & CIDR blocks (IPv4 and IPv6). Written in TypeScript.

npm install @arcanyx/cidr-slicer

Features:

• Parse IP addresses:

  ipv6AddressFromString("2001:db8::").toString()  // "2001:db8::"
  ipv6AddressFromString("2001:db8::").bigIntValue // 42540766411282592856903984951653826560n

• Mask IP addresses w/ a prefix length:

  ipv4AddressFromString("1.1.1.1").mask(16).toString()  // "1.1.0.0"

• Parse CIDR blocks:

  ipv6CidrBlockFromString("2001:db8::/64").prefixLength  // 64

• Slice CIDR blocks into smaller blocks:

  const slices = ipv6CidrBlockFromString("2001:db8::/32").slice(48);
  slices.get(0n).toString();  // "2001:db8::/48"
  slices.get(1n).toString();  // "2001:db8:1::/48"

• Slice CIDR blocks into smaller blocks, and slice those blocks into even smaller blocks:

  const slices = ipv6CidrBlockFromString("2001:db8::/32").slice(48);
  const subslices = slices.get(1n).slice(64);
  subslices.get(1n).toString() // "2001:db8:1:1::/64

Examples

Slice IPv6 CIDR Blocks into smaller blocks.

import {ipv6CidrBlockFromString} from "cidr-slicer";

// Slice a /56 block into /64 block slices.
const block = ipv6CidrBlockFromString("2001:db8::/56");  // Type: CidrBlock<Ipv6Address>
const slices = block.slice(64);  // Type: Ipv6CidrBlockSlices

for (let i = 0n; i < slices.length; i++) {
   // Get and print the i'th block slice.
    const slice = slices.get(i);  // Type: CidrBlock<Ipv6Address>
    console.log(`slice ${i}: ${slice}`);
}
// Console output:
//  slice 0: 2001:db8::/64
//  slice 1: 2001:db8:0:1::/64
//  slice 2: 2001:db8:0:2::/64
//  [...]
//  slice 255: 2001:db8:0:ff::/64

Use Cases

Assigning IPv6 blocks to AWS subnets with AWS CDK

TODO: Write this section

Assigning IPv6 blocks to AWS subnets with Pulumi

TODO: Write this section

Assigning IPv6 blocks to AWS subnets with CDKTF (CDK for Terraform)

TODO: Write this section