diff --git a/Net/DistributedRoutingTable.cs b/Net/DistributedRoutingTable.cs
index a0a042ea..f71daa9b 100644
--- a/Net/DistributedRoutingTable.cs
+++ b/Net/DistributedRoutingTable.cs
@@ -233,7 +233,7 @@ public class DistributedRoutingTable
 		evt = CreateEvent(null, false, false);
 		DrtOpen(pSettings, evt, default, out HDRT h).ThrowIfFailed();
 		hDrt = new((IntPtr)h);
-		selfPin = GCHandle.Alloc(this).AddrOfPinnedObject();
+		selfPin = (IntPtr)GCHandle.Alloc(this, GCHandleType.Normal);
 		Win32Error.ThrowLastErrorIfFalse(RegisterWaitForSingleObject(out drtWaitEvent, evt, DrtEventCallback, selfPin, INFINITE, WT.WT_EXECUTEDEFAULT));
 	}
 
diff --git a/PInvoke/Drt/Drt.cs b/PInvoke/Drt/Drt.cs
index 91382e9c..06f1dfbc 100644
--- a/PInvoke/Drt/Drt.cs
+++ b/PInvoke/Drt/Drt.cs
@@ -13,6 +13,8 @@ namespace Vanara.PInvoke
 	public static partial class Drt
 	{
 		private const string Lib_Drt = "drt.dll";
+		private const string Lib_DrtProv = "drtprov.dll";
+		private const string Lib_DrtTrans = "drttransport.dll";
 
 		/// <summary/>
 		public const uint DRT_PAYLOAD_REVOKED = (1 << 0);
@@ -585,7 +587,7 @@ namespace Vanara.PInvoke
 		/// </returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtcreatederivedkey HRESULT DrtCreateDerivedKey( PCCERT_CONTEXT
 		// pLocalCert, DRT_DATA *pKey );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtCreateDerivedKey")]
 		public static extern HRESULT DrtCreateDerivedKey(PCCERT_CONTEXT pLocalCert, out DRT_DATA pKey);
 
@@ -629,7 +631,7 @@ namespace Vanara.PInvoke
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtcreatederivedkeysecurityprovider HRESULT
 		// DrtCreateDerivedKeySecurityProvider( PCCERT_CONTEXT pRootCert, PCCERT_CONTEXT pLocalCert, DRT_SECURITY_PROVIDER
 		// **ppSecurityProvider );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtCreateDerivedKeySecurityProvider")]
 		public static extern HRESULT DrtCreateDerivedKeySecurityProvider(PCCERT_CONTEXT pRootCert, PCCERT_CONTEXT pLocalCert, out IntPtr ppSecurityProvider);
 
@@ -660,7 +662,7 @@ namespace Vanara.PInvoke
 		/// </returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtcreatednsbootstrapresolver HRESULT
 		// DrtCreateDnsBootstrapResolver( USHORT port, PCWSTR pwszAddress, DRT_BOOTSTRAP_PROVIDER **ppModule );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtCreateDnsBootstrapResolver")]
 		public static extern HRESULT DrtCreateDnsBootstrapResolver(ushort port, [MarshalAs(UnmanagedType.LPWStr)] string pwszAddress, out IntPtr ppModule);
 
@@ -724,7 +726,7 @@ namespace Vanara.PInvoke
 		/// </remarks>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtcreateipv6udptransport HRESULT DrtCreateIpv6UdpTransport(
 		// DRT_SCOPE scope, ULONG dwScopeId, ULONG dwLocalityThreshold, USHORT *pwPort, HDRT_TRANSPORT *phTransport );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtTrans, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtCreateIpv6UdpTransport")]
 		public static extern HRESULT DrtCreateIpv6UdpTransport(DRT_SCOPE scope, uint dwScopeId, uint dwLocalityThreshold, ref ushort pwPort, out HDRT_TRANSPORT phTransport);
 
@@ -752,7 +754,7 @@ namespace Vanara.PInvoke
 		/// </returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtcreatenullsecurityprovider HRESULT
 		// DrtCreateNullSecurityProvider( DRT_SECURITY_PROVIDER **ppSecurityProvider );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtCreateNullSecurityProvider")]
 		public static extern HRESULT DrtCreateNullSecurityProvider(out IntPtr ppSecurityProvider);
 
@@ -808,7 +810,7 @@ namespace Vanara.PInvoke
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtcreatepnrpbootstrapresolver HRESULT
 		// DrtCreatePnrpBootstrapResolver( BOOL fPublish, PCWSTR pwzPeerName, PCWSTR pwzCloudName, PCWSTR pwzPublishingIdentity,
 		// DRT_BOOTSTRAP_PROVIDER **ppResolver );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtCreatePnrpBootstrapResolver")]
 		public static extern HRESULT DrtCreatePnrpBootstrapResolver([MarshalAs(UnmanagedType.Bool)] bool fPublish, [MarshalAs(UnmanagedType.LPWStr)] string pwzPeerName,
 			[Optional, MarshalAs(UnmanagedType.LPWStr)] string pwzCloudName, [Optional, MarshalAs(UnmanagedType.LPWStr)] string pwzPublishingIdentity,
@@ -821,7 +823,7 @@ namespace Vanara.PInvoke
 		/// <returns>None</returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeletederivedkeysecurityprovider void
 		// DrtDeleteDerivedKeySecurityProvider( DRT_SECURITY_PROVIDER *pSecurityProvider );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeleteDerivedKeySecurityProvider")]
 		public static extern void DrtDeleteDerivedKeySecurityProvider(in DRT_SECURITY_PROVIDER pSecurityProvider);
 
@@ -832,7 +834,7 @@ namespace Vanara.PInvoke
 		/// <returns>None</returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeletederivedkeysecurityprovider void
 		// DrtDeleteDerivedKeySecurityProvider( DRT_SECURITY_PROVIDER *pSecurityProvider );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeleteDerivedKeySecurityProvider")]
 		public static extern void DrtDeleteDerivedKeySecurityProvider([In] IntPtr pSecurityProvider);
 
@@ -841,7 +843,7 @@ namespace Vanara.PInvoke
 		/// <returns>None</returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeletednsbootstrapresolver void DrtDeleteDnsBootstrapResolver(
 		// DRT_BOOTSTRAP_PROVIDER *pResolver );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeleteDnsBootstrapResolver")]
 		public static extern void DrtDeleteDnsBootstrapResolver(in DRT_BOOTSTRAP_PROVIDER pResolver);
 
@@ -850,7 +852,7 @@ namespace Vanara.PInvoke
 		/// <returns>None</returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeletednsbootstrapresolver void DrtDeleteDnsBootstrapResolver(
 		// DRT_BOOTSTRAP_PROVIDER *pResolver );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeleteDnsBootstrapResolver")]
 		public static extern void DrtDeleteDnsBootstrapResolver([In] IntPtr pResolver);
 
@@ -884,7 +886,7 @@ namespace Vanara.PInvoke
 		/// </returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeleteipv6udptransport HRESULT DrtDeleteIpv6UdpTransport(
 		// HDRT_TRANSPORT hTransport );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtTrans, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeleteIpv6UdpTransport")]
 		public static extern HRESULT DrtDeleteIpv6UdpTransport(HDRT_TRANSPORT hTransport);
 
@@ -893,7 +895,7 @@ namespace Vanara.PInvoke
 		/// <returns>None</returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeletenullsecurityprovider void DrtDeleteNullSecurityProvider(
 		// DRT_SECURITY_PROVIDER *pSecurityProvider );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeleteNullSecurityProvider")]
 		public static extern void DrtDeleteNullSecurityProvider(in DRT_SECURITY_PROVIDER pSecurityProvider);
 
@@ -902,7 +904,7 @@ namespace Vanara.PInvoke
 		/// <returns>None</returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeletenullsecurityprovider void DrtDeleteNullSecurityProvider(
 		// DRT_SECURITY_PROVIDER *pSecurityProvider );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeleteNullSecurityProvider")]
 		public static extern void DrtDeleteNullSecurityProvider([In] IntPtr pSecurityProvider);
 
@@ -913,7 +915,7 @@ namespace Vanara.PInvoke
 		/// <returns>None</returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeletepnrpbootstrapresolver void DrtDeletePnrpBootstrapResolver(
 		// DRT_BOOTSTRAP_PROVIDER *pResolver );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeletePnrpBootstrapResolver")]
 		public static extern void DrtDeletePnrpBootstrapResolver(in DRT_BOOTSTRAP_PROVIDER pResolver);
 
@@ -924,7 +926,7 @@ namespace Vanara.PInvoke
 		/// <returns>None</returns>
 		// https://docs.microsoft.com/en-us/windows/win32/api/drt/nf-drt-drtdeletepnrpbootstrapresolver void DrtDeletePnrpBootstrapResolver(
 		// DRT_BOOTSTRAP_PROVIDER *pResolver );
-		[DllImport(Lib_Drt, SetLastError = false, ExactSpelling = true)]
+		[DllImport(Lib_DrtProv, SetLastError = false, ExactSpelling = true)]
 		[PInvokeData("drt.h", MSDNShortId = "NF:drt.DrtDeletePnrpBootstrapResolver")]
 		public static extern void DrtDeletePnrpBootstrapResolver([In] IntPtr pResolver);
 
diff --git a/PInvoke/Drt/Vanara.PInvoke.Drt.csproj b/PInvoke/Drt/Vanara.PInvoke.Drt.csproj
index 97518f2f..f1206e4f 100644
--- a/PInvoke/Drt/Vanara.PInvoke.Drt.csproj
+++ b/PInvoke/Drt/Vanara.PInvoke.Drt.csproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <ProjectExtensions>
-    <SupportedDlls>Drt.dll</SupportedDlls>
+    <SupportedDlls>drt.dll;drtprov.dll;drttransport.dll</SupportedDlls>
   </ProjectExtensions>
   <PropertyGroup>
     <Description>PInvoke API (methods, structures and constants) imported from Windows Drt.dll for the Distributed Routing Table (DRT) API.</Description>
diff --git a/UnitTests/Net/Net.csproj b/UnitTests/Net/Net.csproj
index fb211020..06978e0f 100644
--- a/UnitTests/Net/Net.csproj
+++ b/UnitTests/Net/Net.csproj
@@ -4,5 +4,6 @@
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\Net\Vanara.Net.csproj" />
+    <ProjectReference Include="..\..\PInvoke\FirewallApi\Vanara.PInvoke.FirewallApi.vbproj" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/UnitTests/Net/NetTests.cs b/UnitTests/Net/NetTests.cs
index 7be0e12b..226e5b2b 100644
--- a/UnitTests/Net/NetTests.cs
+++ b/UnitTests/Net/NetTests.cs
@@ -2,12 +2,16 @@
 using NUnit.Framework;
 using NUnit.Framework.Internal;
 using System;
+using System.Collections.Generic;
+using System.Diagnostics;
 using System.Runtime.InteropServices;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Xml.Linq;
+using Vanara.InteropServices;
 using Vanara.Net;
 using static Vanara.PInvoke.Dhcp;
+using static Vanara.PInvoke.FirewallApi;
 
 namespace Vanara.PInvoke.Tests;
 
@@ -71,4 +75,63 @@ public class NetTests
 			client.Dispose();
 		}
 	}
+
+	[Test]
+	public void TestDrt()
+	{
+		using var fw = new Firewall();
+		fw.AddApp(Process.GetCurrentProcess().ProcessName, Process.GetCurrentProcess().MainModule.FileName);
+		try
+		{
+			DistributedRoutingTable drt = new(null, DrtBootstrapProvider.CreateDnsBootstrapResolver(null, 0));
+
+		}
+		finally
+		{
+			try { fw.RemoveApp(Process.GetCurrentProcess().MainModule.FileName); } catch { }
+		}
+	}
+
+	private class Firewall : IDisposable
+	{
+		Dictionary<string, ComReleaser<INetFwAuthorizedApplication>> newApps = new();
+		ComReleaser<INetFwMgr> pMgr;
+		ComReleaser<INetFwPolicy> pPol;
+		ComReleaser<INetFwProfile> pProf;
+		ComReleaser<INetFwAuthorizedApplications> pSet;
+
+		public Firewall()
+		{
+			pMgr = ComReleaserFactory.Create(new INetFwMgr());
+			Assert.IsNotNull(pMgr.Item);
+			pPol = ComReleaserFactory.Create(pMgr.Item.LocalPolicy);
+			Assert.IsNotNull(pPol.Item);
+			pProf = ComReleaserFactory.Create(pPol.Item.CurrentProfile);
+			Assert.IsNotNull(pProf.Item);
+			pSet = ComReleaserFactory.Create(pProf.Item.AuthorizedApplications);
+			Assert.IsNotNull(pSet.Item);
+		}
+
+		public void AddApp(string name, string exePath)
+		{
+			var pNewApp = ComReleaserFactory.Create(new INetFwAuthorizedApplication());
+			pNewApp.Item.Name = name;
+			pNewApp.Item.ProcessImageFileName = exePath;
+			pNewApp.Item.Enabled = true;
+			pSet.Item.Add(pNewApp.Item);
+			newApps.Add(exePath, pNewApp);
+		}
+
+		public void Dispose()
+		{
+			pSet.Dispose();
+			pProf.Dispose();
+			pPol.Dispose();
+			pMgr.Dispose();
+			foreach (var app in newApps.Values)
+				app.Dispose();
+		}
+
+		public void RemoveApp(string exePath) => pSet.Item.Remove(exePath);
+	}
 }
\ No newline at end of file