- * Destination MAC can come from
- * - pre-configured mac in case 'dst mac=xx:xx:xx:xx:xx:xx' in config file
- * - src mac from the packet in case 'dst mac=packet' in config file
- * - not written in case 'dst mac=no' in config file
- * - (default - no 'dst mac') src mac from the packet
- * Source MAC can come from
- * - pre-configured mac in case 'src mac=xx:xx:xx:xx:xx:xx' in config file
- * - dst mac from the packet in case 'src mac=packet' in config file
- * - not written in case 'src mac=no' in config file
- * - (default - no 'src mac') if (tx_port) port mac
- * - (default - no 'src mac') if (no tx_port) dst mac from the packet
+ * The destination MAC of the outgoing packet is based on the config file:
+ * - 'dst mac=xx:xx:xx:xx:xx:xx' => the pre-configured mac will be used as dst mac
+ * - 'dst mac=packet' => the src mac of the incoming packet is used as dst mac
+ * - 'dst mac=no' => the dst mac is untouched
+ * - (default - no 'dst mac') => the src mac from the incoming packet is used as dst mac
+ *
+ * The source MAC of the outgoing packet is based on the config file:
+ * - 'src mac=xx:xx:xx:xx:xx:xx' => the pre-configured mac will be used as src mac
+ * - 'src mac=packet' => the dst mac of the incoming packet is used as src mac
+ * - 'src mac=hw' => the mac address of the tx port is used as src mac
+ * An error is returned if there are no physical tx ports
+ * - 'src mac=no' => the src mac is untouched
+ * - (default - no 'src mac') => if there is physical tx port, the mac of that port is used as src mac
+ * - (default - no 'src mac') if there are no physical tx ports the dst mac of the incoming packet
+ is used as src mac