The statement is false. By default, a Nokia MC-LAG is configured to operate in a non-revertive mode. This means that when a failed link or node recovers, traffic will not automatically switch back (revert) to it. The system maintains the traffic on the currently active link to prevent potential instability or traffic disruption that could be caused by link flapping. Revertive behavior must be explicitly enabled by configuring the revert-time parameter within the mc-lag configuration context.

The "True" option is incorrect because it describes revertive behavior, which is not the default for Nokia's MC-LAG implementation. The default non-revertive behavior is designed to prioritize service stability over returning to a specific primary path.

1. Nokia 7450 ESS, 7750 SR, 7950 XRS, and VSR LAG and MC-LAG Guide, SR OS Release 21.10.R1, Document Part Number: 3HE 17313 AAAD TQZZA, Section: MC-LAG Configuration Commands.

Reference Detail: In the description of the revert-time command under the config>lag>mc-lag context, the documentation states: "This command enables revertive operation for an MC-LAG instance... By default, MC-LAG operates in non-revertive mode." This explicitly confirms that the default behavior is non-revertive, and an administrator must configure a revert timer to enable the behavior described in the question.