4A0-105 practice question 16 of 25

When deploying Active/Standby pseudowires, the CE does not require any special configuration

Full set: 156 questions
Answer options
A: TRUE
B: FALSE
Correct Answer:
TRUE
Explanation

The Active/Standby pseudowire (PW) redundancy mechanism is a network-based resiliency feature implemented entirely on the Provider Edge (PE) routers. The PEs manage the signaling, status negotiation (typically using LDP status bits), and traffic forwarding decisions for the active and standby PWs. This entire process is designed to be transparent to the Customer Edge (CE) device. The CE simply connects to the service via a standard Layer 2 interface (e.g., an Ethernet port or a LAG) and is unaware of the underlying dual-homing and failover mechanism occurring within the provider's core network.

Why Incorrect

The alternative, "False," is incorrect. If the statement were false, it would imply that the CE device requires special protocols or configuration settings to participate in the Active/Standby PW redundancy scheme. This contradicts the fundamental design principle of this feature, which is to provide service-level redundancy without imposing any specific requirements or configuration changes on the customer's equipment.

References

1. Nokia 7750 SR OS Services Guide, Release 21.10.R1, Section: Pseudowire Redundancy.

In the chapter on VPLS, under the "Pseudowire Redundancy" section, the documentation explains that active/standby signaling is handled between PEs. It describes the configuration on the PEs (endpoint, precedence) and how the CE is attached via a SAP (Service Access Point). The text implicitly and explicitly confirms that the redundancy logic is confined to the PEs, with no special configuration mentioned for the CE. The CE's connection is a standard service attachment.

2. Nokia Services Architecture (4A0-105) Student Guide, Module 4: Virtual Private LAN Service (VPLS).

The courseware covers VPLS resiliency mechanisms, including multi-homing with Active/Standby pseudowires. It emphasizes that this is a PE-level redundancy solution. The diagrams and explanations show the signaling occurring between the PEs, while the CE is depicted with a standard Ethernet link, illustrating its non-participation in the redundancy protocol itself. The text clarifies that this approach provides transparency to the customer's network.

3. Nokia 7750 SR OS Layer 2 Services and EVPN Guide, Release 21.10.R1, Section: Epipe Spoke-SDP Redundancy.

This section details the use of Active/Standby PWs for Epipe (point-to-point) services. It states, "The CE is not aware of the two connections to the two PEs providing the service." This explicitly confirms that the CE requires no special configuration or awareness of the redundant setup. The failover is handled by the PEs based on the status of the active PW.

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