A network administrator is configuring network redundancy for a mission-critical database server equipped with two physical network interface cards (NICs). The server is connected to two separate, independent standalone switches that do not support multi-chassis link aggregation (MLAG). The administrator configures IEEE 802.3ad Link Aggregation Control Protocol (LACP) bonding on the server's interfaces. Immediately after enabling the bond, network monitoring reports severe packet loss, and both switches log MAC address flapping errors. Which of the following is the most appropriate solution to resolve the connectivity issue while maintaining interface redundancy?
- Reconfigure the server NIC teaming mode to Switch Independent Active-Backup mode.Answer
- BConfigure the server's default gateway to use the physical IP address of the primary switch instead of the virtual IP (VIP).
- CSet the Spanning Tree Protocol (STP) priority on both standalone switches to the highest numerical value available.
- DEnable LACP Active mode on the connected ports of both standalone switches.
Answer
Reconfiguring the server's NIC teaming mode to Switch Independent Active-Backup mode resolves the MAC address flapping while maintaining link redundancy.
IEEE 802.3ad LACP link aggregation requires the participating ports to terminate on a single switch control plane, such as a single switch or stacked switches supporting MLAG. When LACP is enabled across independent standalone switches, the switches see the same MAC address appearing across different unaggregated links, causing MAC address table instability (flapping) and dropped traffic. Reconfiguring the NIC team to Switch Independent Active-Backup mode allows one interface to handle traffic while keeping the other in standby without requiring switch coordination, resolving the conflict while maintaining hardware failover protection.
Step-by-Step Solution
Key Concept
NIC Teaming and Link Aggregation Requirements in High Availability