L2T_STATE_STALE
case L2T_STATE_STALE: return 'S'; /* needs revalidation, but usable */
if (e->state == L2T_STATE_VALID || e->state == L2T_STATE_STALE)
e->state == L2T_STATE_STALE,
e->state = L2T_STATE_STALE;
case L2T_STATE_STALE: /* entry is stale, kick off revalidation */
e->state = L2T_STATE_STALE;