Question

How to Fix error System.Data.SqlClient.SqlException: Login failed for user

Working with my project in debug I have no issues. However running it in IIS I am getting this error:

System.Data.SqlClient.SqlException: Login failed for user 'domain\name-PC$'.

Stack Trace

[SqlException (0x80131904): Login failed for user 'DOMAIN\NAME-PC$'.]

   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +6749670

   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +815

   System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +4515

   System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +84

   System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK) +53

   System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover) +368

   System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout) +6777754

   System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance) +6778255

   System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData) +878

   System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions) +1162

   System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions) +72

   System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) +6781425

   System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) +103

   System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject,

The number one solution I can find through Google is to change the application pool advanced Identity settings which did not work.

I am using IIS 7.5 and I am connecting to SQLServer 2012 my connection string is below.

Connection String

<add name="_DataConnectionString" connectionString="Data Source=01DEV\SQLDEV01;Initial Catalog=_Data;Integrated Security=True;MultipleActiveResultSets=True;Application Name=EntityFramework"

  providerName="System.Data.SqlClient" />

Answer 1

Assuming you're intending to use Windows Authentication to impersonate the service account, you have to set up Windows Authentication in both IIS and ASP.NET.

In IIS, make sure that the Windows Authentication module is added and enabled. Also make sure your application pool is running under a domain account, not a local account.

In ASP.NET make sure the authentication mode attribute is set to "Windows"

<system.web>

    <authentication mode="Windows"/>

 </system.web>