DOT1Q_VID_MIN
for (unsigned vlan = DOT1Q_VID_MIN; vlan <= DOT1Q_VID_MAX;) {
if (first < DOT1Q_VID_MIN || first > DOT1Q_VID_MAX)
if (last < DOT1Q_VID_MIN || last > DOT1Q_VID_MAX ||
if (val < DOT1Q_VID_MIN || val > DOT1Q_VID_MAX)