// works fine
var redis1 = StackExchange.Redis.ConnectionMultiplexer.Connect("127.0.0.1");

// thows
var redis2 = StackExchange.Redis.ConnectionMultiplexer.Connect("localhost");

at System.Threading.Tasks.TaskFactory`1.FromAsyncImpl[TArg1,TArg2](Func`5 beginMethod, Func`2 endFunction, Action`1 endAction, TArg1 arg1, TArg2 arg2, Object state, TaskCreationOptions creationOptions)
at System.Net.Sockets.SocketTaskExtensions.ConnectAsync(Socket socket, String host, Int32 port)
at StackExchange.Redis.SocketManager.BeginConnect(EndPoint endpoint, ISocketCallback callback, ConnectionMultiplexer multiplexer, TextWriter log)
at StackExchange.Redis.PhysicalConnection.BeginConnect(TextWriter log)
at StackExchange.Redis.PhysicalBridge.GetConnection(TextWriter log)
at StackExchange.Redis.ServerEndPoint..ctor(ConnectionMultiplexer multiplexer, EndPoint endpoint, TextWriter log)
at StackExchange.Redis.ConnectionMultiplexer.<ReconfigureAsync>d__119.MoveNext()
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
at StackExchange.Redis.ConnectionMultiplexer.ConnectImpl(Func`1 multiplexerFactory, TextWriter log)
at ConsoleApplication.Program.Main(String[] args)
---> (Inner Exception #0) System.PlatformNotSupportedException: Sockets on this platform are invalid for use after a failed connection attempt, and as a result do not support attempts to connect to multiple endpoints.
at System.Net.Sockets.Socket.BeginConnect(String host, Int32 port, AsyncCallback requestCallback, Object state)
at System.Threading.Tasks.TaskFactory`1.FromAsyncImpl[TArg1,TArg2](Func`5 beginMethod, Func`2 endFunction, Action`1 endAction, TArg1 arg1, TArg2 arg2, Object state, TaskCreationOptions creationOptions)
at System.Net.Sockets.SocketTaskExtensions.ConnectAsync(Socket socket, String host, Int32 port)
at StackExchange.Redis.SocketManager.BeginConnect(EndPoint endpoint, ISocketCallback callback, ConnectionMultiplexer multiplexer, TextWriter log)
at StackExchange.Redis.PhysicalConnection.BeginConnect(TextWriter log)
at StackExchange.Redis.PhysicalBridge.GetConnection(TextWriter log)
at StackExchange.Redis.ServerEndPoint..ctor(ConnectionMultiplexer multiplexer, EndPoint endpoint, TextWriter log)
at StackExchange.Redis.ConnectionMultiplexer.<ReconfigureAsync>d__119.MoveNext()<---

$ dotnet --info
.NET Command Line Tools (1.0.0-preview1-002702)

Product Information:
 Version:     1.0.0-preview1-002702
 Commit Sha:  6cde21225e

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  10.11
 OS Platform: Darwin
 RID:         osx.10.11-x64