A network engineer deploys a Cisco UCS C-Series Server in standalone mode.

Uplink failover enables the Cisco VIC to move traffic from the primary vNIC path to its secondary path when communication through the primary uplink fails. Enabling this function satisfies the first requirement. The failback timeout determines how long the restored primary path must remain operational before traffic automatically returns to it. Setting this timer to a value below five minutes satisfies the recovery requirement while avoiding immediate failback to an unstable link. The default VLAN determines VLAN handling and does not provide path redundancy. Class of service controls traffic priority rather than failover behavior. VN-Tag mode affects adapter virtualization and frame tagging but does not configure primary-to-secondary vNIC recovery. Cisco’s C-Series documentation states that vNICs can fail over when communication problems occur and defines the failback timeout as the period before the primary interface resumes operation. Cisco UCS C-Series vNIC management