M487: use macro for mac address length in main.c
#define mainLOGGING_TASK_STACK_SIZE ( configMINIMAL_STACK_SIZE * 5 )
#define mainLOGGING_MESSAGE_QUEUE_LENGTH ( 25 )
-extern uint8_t ucMACAddress[ 6 ];
+#if ( configENABLED_NETWORKS & AWSIOT_NETWORK_TYPE_ETH )
+extern uint8_t ucMACAddress[ ipMAC_ADDRESS_LENGTH_BYTES ];
+#endif
/* The default IP and MAC address used by the demo. The address configuration
* defined here will be used if ipconfigUSE_DHCP is 0, or if ipconfigUSE_DHCP is
