An existing connection was forcibly closed by the remote host. SQL Server failed with error code 0xc0000000 to spawn a thread to process a new login or connection

Client Side Error Message: An existing connection was forcibly closed by the remote host

System.ApplicationException: Sql Exception with error number 10054 (Tries=0) ---> System.Data.SqlClient.SqlException: A connection was successfully established with the server, but then an error occurred during the login process. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)
at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
at System.Data.SqlClient.SqlConnection.Open()
at yaf.DB.GetConnection()
at yaf.DB.ExecuteNonQuery(SqlCommand cmd)
at yaf.DB.eventlog_create(Object userID, Object source, Object description)

Server Side Error Message: SQL Server failed with error code 0xc0000000 to spawn a thread to process a new login or connection

Event Type: Error
Event Source: MSSQLSERVER
Event Category: (4)
Event ID: 17189
Date: 9/4/2006
Time: 8:52:50 AM
User: N/A
Computer: SQL004
Description:
SQL Server failed with error code 0xc0000000 to spawn a thread to process a new login or connection.
Check the SQL Server error log and the Windows event logs for information about possible related problems. [CLIENT: named pipe]

Resolution

Add the following registry key and reboot the server.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\SycAttackProtect{DWORD} = 0

Related Resources

• More GNE (General Network Error) messages when running SQL Server after installing service pack 1 for Windows Server 2003 and TCP registry key SynAttackProtect
• New Networking Features in Microsoft Windows Server 2003 Service Pack 1
• SynAttackProtect