sql server 2012 客户端连接失败

Question

我的sql server 2012 客户端,连接远程服务器出现如下错误:SQL 服务器2008,2012都一样,而客户端用2008的连接没有问题.

visual studio 2012 连接数据库也是一样错误,vs 2010也没有问题,.net 4.5连接就有问题,.net 4.0也没有问题.

新装的系统什么的,有时没有问题,但会在某天突然出现问题.

无法连接到 192.168.10.80。

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已成功与服务器建立连接，但是在登录前的握手期间发生错误。 (provider: TCP Provider, error: 0 - 指定的网络名不再可用。) (.Net SqlClient Data Provider)

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有关帮助信息，请单击: http://go.microsoft.com/fwlink?ProdName=Microsoft%20SQL%20Server&EvtSrc=MSSQLServer&EvtID=64&LinkId=20476

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服务器名称: 192.168.10.80
错误号: 64
严重性: 20
状态: 0

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程序位置:

   在 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
   在 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
   在 System.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error)
   在 System.Data.SqlClient.TdsParserStateObject.ReadSniSyncOverAsync()
   在 System.Data.SqlClient.TdsParserStateObject.TryReadNetworkPacket()
   在 System.Data.SqlClient.TdsParser.ConsumePreLoginHandshake(Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean& marsCapable)
   在 System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean withFailover)
   在 System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
   在 System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
   在 System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
   在 System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions)
   在 System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   在 System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions)
   在 System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   在 System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   在 System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   在 System.Data.SqlClient.SqlConnection.Open()
   在 Microsoft.SqlServer.Management.SqlStudio.Explorer.ObjectExplorerService.ValidateConnection(UIConnectionInfo ci, IServerType server)
   在 Microsoft.SqlServer.Management.UI.ConnectionDlg.Connector.ConnectionThreadUser()

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指定的网络名不再可用。