DH.NetworkInfo 1.0.1

DH.NetworkInfo

DH.NetworkInfo is a managed Windows network information library for C# developers.

This package is Windows-only.

Features

• Default IP / primary adapter lookup — picks the adapter with a usable default gateway, so you get the one active adapter that actually routes traffic instead of just the first adapter in the list
• Ordered default-gateway adapter list for multi-GW environments
• Adapter enumeration
• Default route enumeration
• IPv4 route table enumeration
• Typed values and display text in the same managed object model
• DHCP, DHCPv6, WINS, DNS suffix, and NetBIOS-related adapter fields
• Strong-name signed managed assembly starting from 1.0.1

Quick Start

using DH.NetworkInfo;

DHNetworkInfo networkInfo = new DHNetworkInfo();
if (!networkInfo.Refresh(DHNetworkInfoRefreshOptions.AllDetails)) {
    return;
}

// Primary adapter = the adapter with a usable IPv4 address AND a usable default gateway.
// When multiple adapters qualify, the one with the lowest route metric wins.
AdapterInfo primaryAdapter = networkInfo.GetPrimaryAdapter();
if (primaryAdapter != null) {
    string ipv4 = primaryAdapter.IPv4Address;      // the machine's "default IP"
    uint ipv4Value = primaryAdapter.IPv4Value;
    string gateway = primaryAdapter.Gateway;        // the default gateway that qualified this adapter
}

Two ways to call the API

• DHNetworkInfo (instance, shown above) — call Refresh() once and reuse the cached snapshot through PrimaryAdapter, Adapters, DefaultRoutes, Routes, and the Get* helper methods.
• DHNetworkInfoReader (static) — same underlying data collection, called directly with no instance or caching, useful for a single one-off lookup:

using DH.NetworkInfo;

AdapterInfo primaryAdapter = DHNetworkInfoReader.GetPrimaryAdapter();
IReadOnlyList<AdapterInfo> adapters = DHNetworkInfoReader.GetAdapters();
IReadOnlyList<AdapterInfo> gatewayAdapters = DHNetworkInfoReader.GetDefaultGatewayAdapters();
IReadOnlyList<RouteInfo> defaultRoutes = DHNetworkInfoReader.GetDefaultRoutes();

DHNetworkInfo.Refresh(options) internally calls DHNetworkInfoReader.GetSnapshot(options), so both styles return identical data — pick whichever fits your usage pattern.

Multi-gateway interpretation

• GetPrimaryAdapter() returns the one adapter selected as the machine's current default path.
• GetDefaultGatewayAdapters() returns every adapter that currently exposes a usable gateway.
• GetDefaultRoutes() returns all current default-route candidates.
• The default-route list is ordered by ascending Metric.
• If multiple default routes share the same Metric, the route attached to the selected primary adapter is listed first.
• The default-gateway adapter list starts in that same route-priority order, then appends any remaining gateway-backed adapters.

using DH.NetworkInfo;

DHNetworkInfo networkInfo = new DHNetworkInfo();
if (!networkInfo.Refresh(DHNetworkInfoRefreshOptions.AllDetails)) {
    return;
}

AdapterInfo primaryAdapter = networkInfo.GetPrimaryAdapter();
IReadOnlyList<RouteInfo> defaultRoutes = networkInfo.DefaultRoutes;

if (primaryAdapter != null) {
    Console.WriteLine("Primary Adapter : " + primaryAdapter.FriendlyName);
    Console.WriteLine("Primary IPv4    : " + primaryAdapter.IPv4Address);
    Console.WriteLine("Gateway         : " + primaryAdapter.Gateway);
}

for (int index = 0; index < defaultRoutes.Count; ++index) {
    RouteInfo route = defaultRoutes[index];
    Console.WriteLine("#{0} nextHop={1} if={2} metric={3}",
        index,
        route.NextHop,
        route.InterfaceAddress,
        route.Metric);
}

Included Samples

• DH.NetworkInfoSampleCSharp
• DH.IPConfigAllCSharp

Notes

• The package targets net46, net48, net6.0-windows, and net8.0-windows.
• The managed package does not depend on the native C++ DLL.
• The managed package is Windows-only and uses Windows networking APIs directly.
• Starting with 1.0.1, the package is strong-name signed. Consumers upgrading from unsigned 1.0.0 may need to rebuild dependent projects.
• DHCP lease timestamps follow the documented public adapter API values exposed by Windows.