cidr-aggregator

Aggregate, reverse, and difference CIDR (IP range) entries. Both IPv4 and IPv6 are supported.

Features

• Aggregate — merge overlapping and adjacent CIDR ranges into a minimal set
• Reverse — compute the complement (all IPs not in the given ranges)
• Difference — subtract one set of ranges from another
• Exclude reserved — filter out special-purpose addresses (RFC 5735, RFC 6890)
• IPv4 + IPv6 — unified API via the IpRange trait

Usage

CLI

Install with uv (recommended):

# Run directly
uvx cidr-aggregator --help

# Or install permanently
uv tool install cidr-aggregator

Or install with Cargo:

cargo install cidr-aggregator --features cli

Pipe CIDRs from stdin:

cat ip-list.txt | cidr-aggregator
curl -s https://example.com/ip-list.txt | cidr-aggregator

Read from a file:

cidr-aggregator -f input.txt -o output.txt

Reverse (compute complement of all input ranges):

cidr-aggregator -r < ranges.txt

Exclude reserved/private IPs:

cidr-aggregator -x < ranges.txt

Show statistics (address count, line count):

cidr-aggregator -s < ranges.txt

Library

Add to your Cargo.toml:

[dependencies]
cidr-aggregator = "0.1"

Aggregate overlapping and adjacent blocks into a minimal set:

use cidr_aggregator::{Aggregator, parse_cidrs};

let (mut v4_ranges, _, _) = parse_cidrs("10.0.0.0/24\n10.0.1.0/24\n10.0.0.128/25");
// Adjacent .0.0/24 + .1.0/24 → .0.0/23;  .0.128/25 is inside the /23
v4_ranges.aggregate();
// Aggregate produces minimal ranges but not necessarily canonical CIDR
// blocks — normalize() is required before export().
v4_ranges.normalize();
assert_eq!(v4_ranges.export(), "10.0.0.0/23");

Chain operations in a pipeline — filter reserved addresses, then reverse:

use cidr_aggregator::{Aggregator, parse_cidrs, IpRange, Ipv6Range};

let (_, v6_ranges, _) = parse_cidrs("2001:db8::/32\n64:ff9b::/96");
println!(
    "{}",
    v6_ranges
        .aggregated()
        .differenced(Ipv6Range::reserved()) // strip RFC 6890 reserved blocks
        // Normalize is required to produce valid CIDR blocks after aggregation
        // and difference, which may leave non-canonical ranges.
        .normalized()
        .reversed()
        .export());

See the API documentation for all available operations.

Web App

Also available as a WASM-powered web app at:

cidr-aggregator.pages.dev

License

MIT OR Apache-2.0