diff --git a/ncsid/src/platforms/nemora/portable/net_types.h b/ncsid/src/platforms/nemora/portable/net_types.h
new file mode 100644
index 0000000..872d94f
--- /dev/null
+++ b/ncsid/src/platforms/nemora/portable/net_types.h
@@ -0,0 +1,37 @@
+#ifndef PLATFORMS_NEMORA_PORTABLE_NET_TYPES_H_
+#define PLATFORMS_NEMORA_PORTABLE_NET_TYPES_H_
+
+#include <stdint.h>
+
+// Buffer big enough for largest frame we expect
+// to receive from EMAC (in bytes)
+//   1500 (max payload IEEE 802.3) +
+//   14 (header) +
+//   4 (crc, if not stripped by EMAC) +
+//   4 (optional VLAN tag, if not stripped by EMAC)
+#define ETH_BUFFER_SIZE 1522
+#define IPV4_ETHERTYPE 0x0800
+#define IPV6_ADDR_SIZE 16
+#define MAC_ADDR_SIZE 6
+
+#ifndef __packed
+#define __packed __attribute__((packed))
+#endif
+
+/* MAC address */
+typedef struct __packed {
+  uint8_t octet[MAC_ADDR_SIZE];  // network order
+} mac_addr_t;
+
+/*
+ * Ethernet header.
+ * Note: This assumes a packet without VLAN tags.
+ * TODO: configure HW to strip VLAN field.
+ */
+typedef struct __packed {
+  mac_addr_t dest;
+  mac_addr_t src;
+  uint16_t ethertype;
+} eth_hdr_t;
+
+#endif  // PLATFORMS_NEMORA_PORTABLE_NET_TYPES_H_