Question

Difficulty: MediumHigh Availability and Redundancy Concepts

During a high-availability audit of a corporate network, a technician evaluates a VRRP pair where Router 1 (10.1.1.2) and Router 2 (10.1.1.3) share Virtual IP (VIP) 10.1.1.1. When Router 1 is powered off for maintenance, workstations on the local subnet immediately lose connectivity to remote networks despite Router 2 assuming the active master role. Troubleshooting reveals that workstations cannot reach their default gateway during the outage. What is the most likely root cause of this failure?

  1. Workstations were configured with the physical IP address of Router 1 (10.1.1.2) as their default gateway instead of the virtual IP address (10.1.1.1).Answer
  2. B
    Workstations were placed on a separate VLAN broadcast domain from the physical interfaces of both routers.
  3. C
    The Spanning Tree Protocol (STP) root bridge priority on Router 2 was set to a higher numerical value than on Router 1.
  4. D
    Workstations were assigned IP addresses and default gateways belonging to different IP subnets.

Answer

Workstations were configured with the physical IP address of Router 1 (10.1.1.2) as their default gateway instead of the virtual IP address (10.1.1.1).
In First Hop Redundancy Protocols (FHRP) such as VRRP or HSRP, hosts must be configured to point to the shared Virtual IP (VIP) as their default gateway. When hosts are instead configured with the physical IP of a specific router, traffic goes strictly to that physical device. When that router shuts down, hosts lose gateway reachability even though the standby router correctly assumes the master VRRP role.

Step-by-Step Solution

1
Analyze the high-availability gateway architecture
Identify that Router 1 (10.1.1.2) and Router 2 (10.1.1.3) form a VRRP group with Virtual IP (VIP) 10.1.1.1.
VRRP creates a shared virtual gateway IP address so end devices have a single redundant default gateway destination.
2
Evaluate the symptom during failover
Router 2 becomes master as intended when Router 1 shuts down, but host workstations lose remote network access.
This indicates that VRRP protocol state transitions are functioning correctly, but client traffic is not reaching the new master router.
3
Determine the host configuration misconfiguration
Clients were using the physical IP of Router 1 rather than the VIP.
For gateway redundancy to work, end hosts must direct their default gateway traffic to the VIP (10.1.1.1) so VRRP can dynamically map the active router's MAC address.

Key Concept

FHRP Virtual Gateway IP Configuration
Estimated Time:1m 30s
Rate this question