350-401 Question 176
Single answerA large enterprise has implemented a wireless network spanning multiple buildings on its campus. The network uses a combination of Layer 2 and Layer 3 roaming to ensure seamless connectivity for mobile users. During a troubleshooting session, the network engineer notices that users experience a brief network disruption when moving between buildings, even though the devices maintain their IP addresses. What is the most likely reason for this issue?
- A
The Layer 2 roaming configuration is missing, causing the device to reauthenticate when moving to a new access point.
- B
The Layer 3 roaming is not configured properly, leading to a delay in the handoff of the IP address between subnets.
- C
The wireless controller is overloaded, causing delays in processing mobility events during roaming.
- D
The devices are configured with static IP addresses, preventing them from seamlessly roaming across Layer 3 boundaries.
Show answer and explanation
Correct answer: B
Explanation
In a wireless network, Layer 3 roaming ensures seamless mobility across different IP subnets by tunneling traffic back to the original subnet or dynamically updating routing information. If Layer 3 roaming is not configured correctly, devices may experience brief disruptions as they attempt to maintain their sessions while transitioning between subnets. This aligns with the symptoms described in the scenario, making improper Layer 3 roaming configuration the most likely cause.
- A. Incorrect.
Layer 2 roaming allows a device to move between access points on the same VLAN without reauthentication. The issue described involves IP address handling, which is unrelated to Layer 2 roaming.
- B. Correct.
Layer 3 roaming involves maintaining an active session while transitioning between different subnets. If improperly configured, it can cause brief disruptions when devices move across Layer 3 boundaries, as seen in this scenario.
- C. Incorrect.
While an overloaded wireless controller can cause roaming delays, the issue described specifically involves IP address handling, which is more closely related to Layer 3 roaming than controller performance.
- D. Incorrect.
Static IP addresses can cause roaming issues, but the question specifies that the devices maintain their IP addresses, which rules out this option as the cause of disruption.