Philiprehberger.IpRange

Parse and match IP addresses against CIDR ranges with IPv4 and IPv6 support.

Installation

dotnet add package Philiprehberger.IpRange

Usage

Parsing and Matching CIDR Ranges

using System.Net;
using Philiprehberger.IpRange;

// Parse a CIDR range and check membership
var range = IpRange.Parse("192.168.1.0/24");
bool match = range.Contains(IPAddress.Parse("192.168.1.42")); // true

// Inspect range boundaries
var cidr = IpCidrRange.Parse("10.0.0.0/8");
Console.WriteLine(cidr.FirstAddress); // 10.0.0.0
Console.WriteLine(cidr.LastAddress);  // 10.255.255.255
Console.WriteLine(cidr.PrefixLength); // 8

Matching Against Multiple Ranges

using System.Net;
using Philiprehberger.IpRange;

// Parse comma-separated CIDR ranges into a list
var list = IpRangeList.Parse("10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16");
bool allowed = list.Contains(IPAddress.Parse("172.16.5.1")); // true

// IPv6 ranges work the same way
var ipv6Range = IpCidrRange.Parse("fe80::/10");
bool isLinkLocal = ipv6Range.Contains(IPAddress.Parse("fe80::1")); // true

Checking Range Overlap

using Philiprehberger.IpRange;

var rangeA = IpCidrRange.Parse("192.168.0.0/16");
var rangeB = IpCidrRange.Parse("192.168.1.0/24");
var rangeC = IpCidrRange.Parse("10.0.0.0/8");

bool overlaps = rangeA.Overlaps(rangeB); // true — rangeB is within rangeA
bool separate = rangeA.Overlaps(rangeC); // false — completely disjoint

Safe Parsing and Address Counts

using Philiprehberger.IpRange;

// TryParse never throws — returns false on invalid input
if (IpCidrRange.TryParse("10.0.0.0/8", out var range))
{
    System.Numerics.BigInteger total = range.AddressCount; // 16777216
}

if (IpRangeList.TryParse("10.0.0.0/8, 172.16.0.0/12", out var list))
{
    Console.WriteLine(list!.Count); // 2
}

Classifying IP Addresses

using System.Net;
using Philiprehberger.IpRange;

// Get the full classification for an address
var classification = IpClassification.Classify(IPAddress.Parse("192.168.1.1"));
Console.WriteLine(classification); // Private

// Quick checks via IpRange helpers
bool isPrivate  = IpRange.IsPrivate(IPAddress.Parse("10.0.0.1"));    // true
bool isLoopback = IpRange.IsLoopback(IPAddress.Parse("127.0.0.1")); // true

API

IpRange

Member	Description
Parse(string cidr)	Parse a CIDR string and return an IpCidrRange
IsPrivate(IPAddress address)	Check if the address is in a private range
IsLoopback(IPAddress address)	Check if the address is a loopback address

IpCidrRange

Member	Description
Network	The network address
PrefixLength	The CIDR prefix length
FirstAddress	First address in the range
LastAddress	Last address in the range
AddressCount	Total number of addresses in the range (BigInteger)
Contains(IPAddress)	Check if an address falls within this range
Contains(IpCidrRange)	Check if another range is fully contained
Overlaps(IpCidrRange)	Check if two ranges share any common addresses
Parse(string cidr)	Parse a CIDR notation string
TryParse(string?, out IpCidrRange)	Try to parse a CIDR string; returns false on invalid input

IpRangeList

Member	Description
Parse(string ranges)	Parse comma-separated CIDR ranges
TryParse(string?, out IpRangeList?)	Try to parse comma-separated CIDR ranges; returns false on invalid input
Contains(IPAddress)	Check if any range contains the address
Count	Number of CIDR ranges in the list

IpClassification

Member	Description
Classify(IPAddress)	Returns the classification (Private, Loopback, LinkLocal, Public)
IsPrivate(IPAddress)	Check for private ranges (10.0/8, 172.16/12, 192.168/16, fc00::/7)
IsLoopback(IPAddress)	Check for loopback (127.0.0.1, ::1)
IsLinkLocal(IPAddress)	Check for link-local (169.254/16, fe80::/10)

Development

dotnet build src/Philiprehberger.IpRange.csproj --configuration Release

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License

MIT