Examkin

Question

Difficulty: Very hardRemote Access and Out-of-Band Management

During a physical fiber cut, an enterprise branch site experiences complete loss of its primary and secondary WAN transport links. Network engineers must urgently perform low-level command-line reconfiguration on the core switches and execute a hard power cycle on an unresponsive edge router at the location. Which of the following infrastructure deployment models provides secure emergency administrative access to these hardware assets without depending on the production transport network?

  1. Connecting a dedicated terminal server and switched Power Distribution Unit (PDU) to an isolated cellular gateway, managing serial console lines using SSH and power sockets using HTTPS.Answer
  2. B
    Configuring an IP-KVM switch attached to the edge router's primary Ethernet interface and initiating remote console access via Telnet over port 22.
  3. C
    Deploying SNMPv2c management agents configured to broadcast serial diagnostic traps over UDP port 161 across the production gateway during link degradation events.
  4. D
    Establishing a Virtual Network Computing (VNC) graphical desktop bridge across internal LAN interfaces using connectionless UDP port 23.

Answer

Connecting a dedicated terminal server and switched Power Distribution Unit (PDU) to an isolated cellular gateway, managing serial console lines using SSH and power sockets using HTTPS.
Out-of-band (OOB) management provides a dedicated, secondary path into network infrastructure that functions even when the primary production network fails completely. Combining a cellular gateway with a console terminal server and a remotely managed switched PDU enables network engineers to establish encrypted SSH serial console sessions to configure switches and access HTTPS management pages to cycle power on frozen hardware.

Step-by-Step Solution

1
Analyze network failure constraints.
Primary and secondary in-band WAN transport links are completely down, ruling out any management system reliant on production IP routing pathways.
Out-of-band (OOB) connectivity must utilize an independent communication path such as cellular modems or POTS lines.
2
Evaluate access requirements for hardware recovery.
Serial console access (terminal server) is required for CLI changes on headless devices, and remote power control (switched PDU) is required to hard reboot unresponsive routers.
In-band administrative protocols (SSH/RDP to primary IP addresses) are unavailable when network OS components or transport interfaces crash.
3
Evaluate transport security and protocol characteristics.
SSH (TCP port 22) and HTTPS (TCP port 443) provide strong encryption over the cellular out-of-band link, while Telnet, SNMPv2c, and incorrect UDP protocol selections introduce severe security vulnerabilities or total protocol failures.
Security mandates encrypted administration even over out-of-band channels.

Key Concept

Out-of-Band (OOB) Remote Management Architecture
Rate this question

Topics

Remote Access and Out-of-Band Management

More questions from this topic