vpn - DotRas 1.3 dial created Vpn entry error from application but not from Windows

Question

我正在使用 dotras 创建一个 vpn 连接。当我尝试使用 dotras dial async 方法连接到 vpn 时，它不起作用：

“错误 718：连接被终止，因为远程计算机没有及时响应”。

所以我尝试通过windows界面连接到我刚刚创建的vpn连接，它工作得很好。奇怪的是，然后我尝试通过 dotras 方法再次连接，它成功了！

所以，如果我尝试先通过 dotras 连接，我不能，但如果我先通过 windows 连接，断开连接，然后通过 dotras 再次连接它可以工作。

我使用的是 Windows 10 pro 和 Windows 2012 服务器，DotRas 的版本是 1.3

这是我的代码：

     RasPhoneBook _allUsersPhoneBook;
            public RasPhoneBook allUsersPhoneBook
            {
                get
                { 
                    _allUsersPhoneBook = new RasPhoneBook();
                    _allUsersPhoneBook.Open(RasPhoneBook.GetPhoneBookPath(RasPhoneBookType.AllUsers));

                    return _allUsersPhoneBook;
                }
                set
                {
                    _allUsersPhoneBook = value;
                }
            }
         private RasDialer _dialer;
                public RasDialer dialer
                {
                    get
                    {
                       if (_dialer== null)
                        {
                            _dialer = new RasDialer();
                            _dialer.Error += new EventHandler<ErrorEventArgs>(Dialer_Error);
                            _dialer.StateChanged += new EventHandler<StateChangedEventArgs>(Dialer_StateChanged);                    
                            _dialer.EntryName = connectionName;
                            _dialer.PhoneBookPath = allUsersPhoneBook.Path;                        
                        }

                        return _dialer;
                    }
                    set
                    {
                        _dialer = value;
                    }
                }

//Here I create the connection entry or if already exists update its properties
         public void CreateOrUpdate()
                {
                    using (dialer)
                    {
                        using (var allUsersPhoneBookLocal = new RasPhoneBook())
                        {
                            allUsersPhoneBookLocal.Open(RasPhoneBook.GetPhoneBookPath(RasPhoneBookType.AllUsers));                   
                            if (allUsersPhoneBook.Entries.Contains(connectionName))
                            {
                                allUsersPhoneBookLocal.Entries[connectionName].PhoneNumber = serverAddress;
                                allUsersPhoneBookLocal.Entries[connectionName].VpnStrategy = RasVpnStrategy;
                                allUsersPhoneBookLocal.Entries[connectionName].Device = RasDevice;
                                allUsersPhoneBookLocal.Entries[connectionName].Options.RemoteDefaultGateway = false;
                                allUsersPhoneBookLocal.Entries[connectionName].Options.IPv6RemoteDefaultGateway = false;
                                allUsersPhoneBookLocal.Entries[connectionName].Options.CacheCredentials = true;
                                allUsersPhoneBookLocal.Entries[connectionName].UpdateCredentials(new System.Net.NetworkCredential(userName, passWord));

                                allUsersPhoneBookLocal.Entries[connectionName].Update();

                            }
                            else
                            {   
                                RasEntry entry = RasEntry.CreateVpnEntry(connectionName, serverAddress, RasVpnStrategy.IkeV2Only,
                                RasDevice);


                                entry.EncryptionType = RasEncryptionType.Optional;                                            

                                entry.Options.IPv6RemoteDefaultGateway = false;
                                entry.Options.RemoteDefaultGateway = false;
                                entry.Options.CacheCredentials = true;


                                /*
                                dialer.EntryName = connectionName;
                                dialer.Credentials = new System.Net.NetworkCredential(userName, ConvertToSecureString(passWord));                       

                                dialer.PhoneBookPath = allUserPhoneBookPath;
                                */


                                allUsersPhoneBook.Entries.Add(entry);
                                entry.UpdateCredentials(new System.Net.NetworkCredential(userName, ConvertToSecureString(passWord)));
                                // 26 means eap-mschapv2 username/password
                                entry.UpdateCredentials(new System.Net.NetworkCredential(userName, ConvertToSecureString(passWord)));
                               // entry.Options.RequireEap = true;
                                entry.CustomAuthKey = 26;
                                entry.Update();
                                entry.VpnStrategy = RasVpnStrategy;
                                entry.Update();

                            }
                        }
                    }
                }

//here I dial the connection

          public RasHandle Dial()
            {
                RasHandle handle = null;
                try
                {
                    using (allUsersPhoneBook)
                    {
                        if (allUsersPhoneBook.Entries.Contains(connectionName))
                        {
                            handle = dialer.DialAsync();                           
                        }
                    }
                    return handle;
                }
                catch (Exception)
                {
                    throw;
                }
            }