+#define ETHER_ADDR_FMT_SIZE 18
+/**
+ * Format 48bits Ethernet address in pattern xx:xx:xx:xx:xx:xx.
+ *
+ * @param buf
+ * A pointer to buffer contains the formatted MAC address.
+ * @param size
+ * The format buffer size.
+ * @param ea_to
+ * A pointer to a ether_addr structure.
+ */
+static inline void
+ether_format_addr(char *buf, uint16_t size,
+ const struct ether_addr *eth_addr)
+{
+ snprintf(buf, size, "%02X:%02X:%02X:%02X:%02X:%02X",
+ eth_addr->addr_bytes[0],
+ eth_addr->addr_bytes[1],
+ eth_addr->addr_bytes[2],
+ eth_addr->addr_bytes[3],
+ eth_addr->addr_bytes[4],
+ eth_addr->addr_bytes[5]);
+}
+