esaProbeInner2VlanTagEnabled is a read-write true/false flag, not applicable to Y.1731 probes, controlling whether the probe adds a second inner VLAN tag to its test frames. An administrator enables it when the monitored service is carried over a double-tagged (QinQ-style) path and the test traffic needs to match that tagging structure to be treated the same way as real customer traffic. For example, enabling this on a probe testing a service nested inside a provider's outer VLAN and a customer's inner VLAN ensures the test frames are switched along the same path as the customer's actual double-tagged traffic.