Examkin

Question

Difficulty: MediumHigh Availability and Redundancy Concepts

An enterprise implements Virtual Router Redundancy Protocol (VRRP) across two core switches to provide high availability for client devices on a production VLAN. During a scheduled test, the primary switch is powered down, and network logs confirm that the standby switch successfully transitions to the master role. However, workstations on the VLAN immediately lose external network connectivity and fail to recover. Diagnostics show that VRRP advertisement packets and virtual MAC transitions operated correctly. Which of the following host misconfigurations is the most likely cause of this connectivity failure?

  1. Workstations were configured with the primary switch's physical interface IP address as their default gateway rather than the virtual IP address shared by the redundancy group.Answer
  2. B
    Workstations were assigned a higher numerical Spanning Tree Protocol priority value than the secondary switch, preventing trunk negotiation.
  3. C
    Workstations were configured with a default gateway residing on a separate subnet that requires an active DHCP relay agent to resolve.
  4. D
    Workstations were isolated into a dedicated broadcast domain that restricts inter-VLAN communication to physical MAC addresses.

Answer

Workstations were configured with the primary switch's physical interface IP address as their default gateway rather than the virtual IP address shared by the redundancy group.
For First Hop Redundancy Protocols (such as VRRP or HSRP) to provide seamless failover, client workstations must use the Virtual IP (VIP) assigned to the router redundancy group as their default gateway. When the active router fails, the standby router takes ownership of the Virtual IP and virtual MAC address. If workstations are statically or dynamically configured with the physical interface IP of the primary router instead of the VIP, their traffic continues targeting the failed physical interface, breaking outbound connectivity despite a successful protocol failover.

Step-by-Step Solution

1
Analyze First Hop Redundancy Protocol (FHRP) operational requirements.
FHRP protocols like VRRP and HSRP create a Virtual IP (VIP) and Virtual MAC address that are shared between redundant routers.
Client endpoints must send outbound traffic to the Virtual IP so that whichever router holds the active/master role can process the frames seamless to the client.
2
Evaluate the failure symptom described in the scenario.
The backup switch successfully assumed the Master role, meaning VRRP failover executed properly at the network layer.
If clients lose connectivity despite a successful VRRP failover, client traffic is directed to a specific physical hardware address rather than the virtual gateway.
3
Identify the client-side configuration error.
Clients configured with the physical interface IP of the primary router lose access when that specific device fails because their packets are sent to an inactive physical node rather than the virtual gateway.
Configuring hosts with the Virtual IP (VIP) ensures traffic is dynamically serviced by whichever switch currently holds the master role.

Key Concept

FHRP Virtual Gateway IP Configuration
Rate this question

Topics

High Availability and Redundancy Concepts

More questions from this topic