IF_STA_LOOPBACK
iface->state = IF_STA_LOOPBACK;
{IF_STA_ANY, IF_EVT_LOOP, IF_ACT_RST, IF_STA_LOOPBACK},
{IF_STA_LOOPBACK, IF_EVT_UNLOOP, IF_ACT_NOTHING, IF_STA_DOWN},
case IF_STA_LOOPBACK:
iface->state & IF_STA_LOOPBACK) {
iface->state = IF_STA_LOOPBACK;
{IF_STA_ANY, IF_EVT_LOOP, IF_ACT_RST, IF_STA_LOOPBACK},
{IF_STA_LOOPBACK, IF_EVT_UNLOOP, IF_ACT_NOTHING, IF_STA_DOWN},
case IF_STA_LOOPBACK:
if (iface->state & IF_STA_LOOPBACK) {