Overview#Using LDAP over IPC Mechanisms (LDAPI) When both the LDAP client and server reside on the same machine, communication efficiency can be greatly improved using host- specific IPC mechanisms instead of a TCP session.
Such mechanisms can also implicitly provide the client's identity to the server for extremely lightweight authentication.
Using LDAP over IPC Mechanisms document describes the implementation of LDAP over Unix IPC that has been in use in OpenLDAP since January 2000, including the URL format used to specify an IPC session.
Using LDAP over IPC Mechanisms allows LDAP connections to run over Inter-Process Communication (IPC) connections, which it is said provides that LDAP operations can run over Unix sockets. These connections are much faster and more secure than regular LDAP connections.