Only use IPv6 if available

3 files changed, 6 insertions, 6 deletions

diff --git a/src/System.Net.Security/tests/FunctionalTests/CertificateValidationClientServer.cs b/src/System.Net.Security/tests/FunctionalTests/CertificateValidationClientServer.cs
index e140430c2d..cef721fc25 100644
--- a/src/System.Net.Security/tests/FunctionalTests/CertificateValidationClientServer.cs
+++ b/src/System.Net.Security/tests/FunctionalTests/CertificateValidationClientServer.cs
@@ -43,7 +43,7 @@ namespace System.Net.Security.Tests
         [InlineData(true)]
         public async Task CertificateValidationClientServer_EndToEnd_Ok(bool useClientSelectionCallback)
         {
-            IPEndPoint endPoint = new IPEndPoint(IPAddress.IPv6Loopback, 0);
+            IPEndPoint endPoint = new IPEndPoint(Socket.OSSupportsIPv6 ? IPAddress.IPv6Loopback : IPAddress.Loopback, 0);
             var server = new TcpListener(endPoint);
             server.Start();
 
@@ -63,7 +63,7 @@ namespace System.Net.Security.Tests
                 _clientCertificateRemovedByFilter = true;
             }
 
-            using (var clientConnection = new TcpClient(AddressFamily.InterNetworkV6))
+            using (var clientConnection = new TcpClient(Socket.OSSupportsIPv6 ? AddressFamily.InterNetworkV6 : AddressFamily.InterNetwork))
             {
                 IPEndPoint serverEndPoint = (IPEndPoint)server.LocalEndpoint;
 
diff --git a/src/System.Net.Security/tests/FunctionalTests/ClientAsyncAuthenticateTest.cs b/src/System.Net.Security/tests/FunctionalTests/ClientAsyncAuthenticateTest.cs
index 50f37d2169..dd48a96d3b 100644
--- a/src/System.Net.Security/tests/FunctionalTests/ClientAsyncAuthenticateTest.cs
+++ b/src/System.Net.Security/tests/FunctionalTests/ClientAsyncAuthenticateTest.cs
@@ -150,10 +150,10 @@ namespace System.Net.Security.Tests
         {
             _log.WriteLine("Server: " + serverSslProtocols + "; Client: " + clientSslProtocols);
 
-            IPEndPoint endPoint = new IPEndPoint(IPAddress.IPv6Loopback, 0);
+            IPEndPoint endPoint = new IPEndPoint(Socket.OSSupportsIPv6 ? IPAddress.IPv6Loopback : IPAddress.Loopback, 0);
 
             using (var server = new DummyTcpServer(endPoint, encryptionPolicy))
-            using (var client = new TcpClient(AddressFamily.InterNetworkV6))
+            using (var client = new TcpClient(Socket.OSSupportsIPv6 ? AddressFamily.InterNetworkV6 : AddressFamily.InterNetwork))
             {
                 server.SslProtocols = serverSslProtocols;
                 await client.ConnectAsync(server.RemoteEndPoint.Address, server.RemoteEndPoint.Port);
diff --git a/src/System.Net.Security/tests/FunctionalTests/ServerAsyncAuthenticateTest.cs b/src/System.Net.Security/tests/FunctionalTests/ServerAsyncAuthenticateTest.cs
index 68e845e56c..c45c488f0f 100644
--- a/src/System.Net.Security/tests/FunctionalTests/ServerAsyncAuthenticateTest.cs
+++ b/src/System.Net.Security/tests/FunctionalTests/ServerAsyncAuthenticateTest.cs
@@ -107,11 +107,11 @@ namespace System.Net.Security.Tests
             int timeOut = expectedToFail ? TestConfiguration.FailingTestTimeoutMiliseconds
                 : TestConfiguration.PassingTestTimeoutMilliseconds;
 
-            IPEndPoint endPoint = new IPEndPoint(IPAddress.IPv6Loopback, 0);
+            IPEndPoint endPoint = new IPEndPoint(Socket.OSSupportsIPv6 ? IPAddress.IPv6Loopback : IPAddress.Loopback, 0);
             var server = new TcpListener(endPoint);
             server.Start();
 
-            using (var clientConnection = new TcpClient(AddressFamily.InterNetworkV6))
+            using (var clientConnection = new TcpClient(Socket.OSSupportsIPv6 ? AddressFamily.InterNetworkV6 : AddressFamily.InterNetwork))
             {
                 IPEndPoint serverEndPoint = (IPEndPoint)server.LocalEndpoint;