使用ldap for PHP完成连接时？

Question

I'm trying to understand PHP's ldap function in order to debug an app.

The authentication flow is like following:

ldap_connect($host, $port);

ldap_set_option($ds, $option);

ldap_bind($ds, $rdn, $pwd);

ldap_search($smth);

ldap_get_entries($smtgelse);

ldap_close($ds);

The error I get is:

The gateway did not receive a timely response from the upstream server or application.

I suspect a firewall to block the response, but I put a logger to see which statment is blocking, it's the ldap_bind one's.

If it's a network issue it should block on the ldap_connect statment shouldn't it?

Answer 1

From the PHP documentation - http://php.net/ldap_connect:

When OpenLDAP 2.x.x is used, ldap_connect() will always return a resource as
it does not actually connect but just initializes the connecting parameters.
The actual connect happens with the next calls to ldap_* funcs, usually with
ldap_bind().