17.3 LDAP Protocol Data Units

Protocol data units are described using the ASN.1 syntax, and they are transferred using the BER coding subset. LDAP includes the following types of operations (each of them has defined inquiry and reply formats):

• bind: Allows authentication information to be exchanged between a client and a server (i.e., user authentication and establishing the session).
• unbind: Termination of the user’s session.
• search: Operation for searching in the DIT. Within a reply, the client receives one of the following types: entry (convenient item), reference to another server, and end of inquiry processing.
• modify: Modification of an entry.
• add: Adds new entry.
• del: Deletes an entry.
• modifyDN: Changes entry’s DN (name) enabling moving the entry within the DIT.
• compare: Testing whether the entry with a specific DN has the required value of a specific attribute.
• abandon: Termination of a currently running operation.
• extended: Enables transfer of various messages between a client...