Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) — Question 589

An engineer receives a report that an application exhibits poor performance. On the switch where the server is connected, this syslog message is visible: SW_MATM-4-MACFLAP_NOTIF: Host 0054.3962.7651 in vlan 14 is flapping between port Gi1/0/1 and port Gi1/0/2.

What is causing the problem?

Answer options

• A. undesirable load-balancing configuration on the switch
• B. invalid port channel configuration on the switch
• C. wrong SFP+ and cable connected between the server and the switch
• D. failed NIC on the server

Correct answer: B

Explanation

The correct answer is B because the MAC flap indicates that the switch is unable to consistently determine the port where the MAC address is located, which is typically due to an invalid port channel configuration. Options A, C, and D do not directly address the MAC flap issue, as they relate to different types of configuration or hardware problems that would not cause the specific symptoms described.