正解:D
Comprehensive and Detailed Explanation:
LDAP over SSL (LDAPS)usesport 636to providesecure, encrypted authenticationfor directory services.
Breakdown of Options:
* A. SMTP (Simple Mail Transfer Protocol)- Usesport 25, not 636.
* B. Syslog- Usesport 514 (UDP),not 636.
* C. TFTP (Trivial File Transfer Protocol)- Usesport 69 (UDP),not 636.
* D. LDAPS (Lightweight Directory Access Protocol Secure)-#Correct answer.Usesport 636for secure directory authentication.