public static VnicType vnicType(String portName) {
        if (portName.startsWith(PORT_NAME_PREFIX_VM) ||
                portName.startsWith(PORT_NAME_VHOST_USER_PREFIX_VM)) {
            return VnicType.NORMAL;
        } else if (isDirectPort(portName)) {
            return VnicType.DIRECT;
        } else {
            return VnicType.UNSUPPORTED;
        }
    }
@Test
    public void testVnicType() {
        String portNameNormalTap = "tap123456789ab";
        String portNameNormalVhu = "tap123456789ab";
        String portNameNormalCavium = "enp1f2s3";
        String portNameUnsupported = "123456789ab";

        assertEquals(vnicType(portNameNormalTap), Constants.VnicType.NORMAL);
        assertEquals(vnicType(portNameNormalVhu), Constants.VnicType.NORMAL);
        assertEquals(vnicType(portNameNormalCavium), Constants.VnicType.DIRECT);
        assertEquals(vnicType(portNameUnsupported), Constants.VnicType.UNSUPPORTED);
    }