Question

Difficulty: MediumNetworking Ports and Protocols

A network administrator is setting up ingress firewall rules for a central management server. The server must receive remote system log messages from network switches and perform encrypted directory queries against an enterprise domain controller. Which of the following port and protocol combinations should be permitted on the firewall? (Select TWO).

  1. UDP port 514Answer
  2. TCP port 636Answer
  3. C
    TCP port 389
  4. D
    UDP port 67

Answer

The firewall rules must permit UDP port 514 for Syslog logging and TCP port 636 for LDAPS encrypted directory queries.
Centralized logging applications rely on the Syslog protocol running over UDP port 514. Secure directory services (LDAPS) encrypt communication over TLS/SSL on TCP port 636. Therefore, allowing UDP port 514 and TCP port 636 satisfies both firewall requirements.

Step-by-Step Solution

1
Identify the protocol required for receiving system log messages.
Syslog standard protocol operates on UDP port 514.
Centralized logging services default to Syslog on UDP 514.
2
Identify the protocol required for secure directory queries.
LDAPS (LDAP over SSL/TLS) operates on TCP port 636.
Unencrypted LDAP uses port 389, but secure directory authentication requires LDAPS on port 636.

Key Concept

Standard Network Service Ports (Syslog and LDAPS)
Rate this question