db connection uses an anonymous logon instead of the domain user I have this PHP code running under IIS:

$serverName = "someServer\someServer";
$connectionInfo = array( "Database"=&gt;"SOME_DB");

$conn = sqlsrv_connect( $serverName, $connectionInfo);

if( $conn ) {
     echo "Connection established.&lt;br /&gt;";
}else{
     echo "Connection could not be established.&lt;br /&gt;";
     die( print_r( sqlsrv_errors(), true));
}


When I try to visit the page, I get the error:


  [Microsoft][SQL Server Native Client 10.0][SQL Server]Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'.


Which is confusing, as the documentation here says "The connection will be attempted using Windows Authentication".

The flow of this is:


User using x Windows account on workstation1 visits this website hosted on server1
server1 executes above PHP code and tries to retrieve data from server2 using y Windows account (y is defined in the IIS settings, under Application Pools->Identity)
Windows account y has access to the database


The IIS pool is running under a Windows domain user "domainadm" which has access to the SOME_DB database and the server it sits on.

Why is it trying to authenticate anonymously and how can I fix this so it runs under the user the IIS pool is running as?

In php.ini:

fastcgi.impersonate = 1;


Checking the Authentication section in IIS, the only options I have are "Anonymous Authentication" or "ASP.NET Impersonation". No Windows authentication?

Anonymous is currently enabled, which gives the error above. If I switch to the ASP.NET one I instead get this error when visiting the page:


  500 - Internal server error. There is a problem with the resource you are looking for, and it cannot be displayed.
Reading the manual I found something relevant:


  For example IIS 7, in its default configuration, has anonymous
  authentication enabled with built-in user account IUSR used as a
  default identity. This means that in order for IIS to execute PHP
  scripts, it is necessary to grant IUSR account read permission on
  those scripts. If PHP applications need to perform write operations on
  certain files or write files into some folders then IUSR account
  should have write permission to those.


And iis.net has the following relevant information:


  This built-in account does not need a password and will be the default
  identity that is used when anonymous authentication is enabled. If you
  look in the applicationHost.config file you will see the following
  definition:
  
  &lt;anonymousAuthentication enabled="true" userName="IUSR" defaultLogonDomain="" /&gt;
  
  This tells IIS to use the new built-in
  account for all anonymous authentication requests.


Hope it helps