This field (SnmpAdminString) names the network-control policy actually in effect at runtime on a port-channel that bundles multiple NAS-storage-connectivity (Estc) ports together for one storage target, after policy resolution. Because UCS can inherit or override policies at several levels, comparing this operational value against the configured nwCtrlPolicyName on this NAS-storage port-channel is how an admin confirms the policy that's really active isn't silently different from the one they assigned. Seeing 'default' here despite a custom policy being configured would flag a policy-resolution issue worth chasing on this specific link.