diff --git a/inarp.c b/inarp.c
new file mode 100644
index 0000000..eb16d5a
--- /dev/null
+++ b/inarp.c
@@ -0,0 +1,346 @@
+/******************************************************************************
+*	Copyright 2016 Foxconn
+*
+*	Licensed under the Apache License, Version 2.0 (the "License");
+*	you may not use this file except in compliance with the License.
+*	You may obtain a copy of the License at
+*
+*		http://www.apache.org/licenses/LICENSE-2.0
+*
+*	Unless required by applicable law or agreed to in writing, software
+*	distributed under the License is distributed on an "AS IS" BASIS,
+*	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+*	See the License for the specific language governing permissions and
+*	limitations under the License.
+******************************************************************************/
+#define MAX_SERVER_NODE 24
+#define SKU1_MAX_SERVER_NODES 24
+
+#define ETH_ARP_FRAME_LEN (	sizeof(struct ethhdr)+\
+							sizeof(struct arphdr)+\
+							((ETH_ALEN+4)*2)\
+							)
+
+struct ARP_DATA {
+	unsigned char src_mac [ETH_ALEN];//source mac addr
+	unsigned char src_ip  [4];		//source ip addr
+	unsigned char dest_mac[ETH_ALEN];//dest mac addr
+	unsigned char dest_ip [4];		//dest ip 
+};
+struct ETH_ARP_PACKET {
+	struct ethhdr eh;
+	struct arphdr arp;
+	struct ARP_DATA arp_data;
+};
+
+struct ETH_ARP_PACKET *inarp_req;
+
+static          char based_mac[6] = {0,0,0,0,0,0};
+int send_arp_packet(int fd,
+					int ifindex,
+					struct ETH_ARP_PACKET *eth_arp,
+					__be16 ar_op,
+					unsigned char *src_mac,
+					unsigned char *src_ip,
+					unsigned char *dest_mac,
+					unsigned char *dest_ip
+					)
+{
+	int send_result = 0;
+	struct ethhdr *eh = &eth_arp->eh;
+	struct arphdr *arp = &eth_arp->arp;
+	struct ARP_DATA *arp_data = &eth_arp->arp_data;
+	/*target address*/
+	struct sockaddr_ll socket_address;
+	/*prepare sockaddr_ll*/
+	/*RAW communication*/
+	socket_address.sll_family   = PF_PACKET;	
+	/*we don't use a protocoll above ethernet layer
+	  ->just use anything here*/
+	socket_address.sll_protocol = htons(ETH_P_ARP);
+	/*index of the network device
+	see full code later how to retrieve it*/
+	socket_address.sll_ifindex  = ifindex;
+	/*ARP hardware identifier is ethernet*/
+	socket_address.sll_hatype   = ARPHRD_ETHER;
+	/*target is another host*/
+	socket_address.sll_pkttype  = PACKET_OTHERHOST;
+	/*address length*/
+	socket_address.sll_halen    = ETH_ALEN;		
+	memcpy(socket_address.sll_addr, dest_mac, ETH_ALEN);
+	/*set the frame header*/
+	memcpy((void*)eh->h_dest, (void*)dest_mac, ETH_ALEN);
+	memcpy((void*)eh->h_source, (void*)src_mac, ETH_ALEN);
+	eh->h_proto = htons(ETH_P_ARP);
+	/*fill InARP request data for ethernet + ipv4*/
+	arp->ar_hrd = htons(ARPHRD_ETHER);
+	arp->ar_pro = htons(ETH_P_ARP);
+	arp->ar_hln = ETH_ALEN;
+	arp->ar_pln = 4;
+	arp->ar_op  = htons(ar_op);
+	//fill arp ethernet mac & ipv4 info
+	arp_data = (void*)(arp + 1);
+	memcpy(arp_data->src_mac , (void*)src_mac, ETH_ALEN);	//source mac addr
+	memcpy(arp_data->src_ip  , src_ip, 4);					//source ip addr
+	memcpy(arp_data->dest_mac, (void*)dest_mac, ETH_ALEN);	//dest mac addr
+	memcpy(arp_data->dest_ip , dest_ip, 4);					//dest ip 
+	/*send the packet*/
+	send_result = sendto(fd, eth_arp, ETH_ARP_FRAME_LEN, 0, 
+	      (struct sockaddr*)&socket_address, sizeof(socket_address));
+	if (send_result == -1) {
+   		printf("sendto: [%s]\n", strerror(errno));
+	}
+	return send_result;
+}
+void show_mac_addr(char *name, unsigned char *mac_addr)
+{
+	int i;
+	printf("%s MAC address: ", name);
+	for( i = 0; i < 6; i++ )
+    {
+        printf("%.2X%c", (unsigned char)mac_addr[i], (i == 5) ? '\n': ':');
+    }
+	return;
+}
+void show_ip_addr(char *desc, unsigned char *ip_addr)
+{
+	int i;
+    printf("%s IPv4 address: ", desc);
+	for(i = 0; i < 4; i++ )
+    {
+	    printf("%d%c", (unsigned char)ip_addr[i], (i == 3) ? '\n': '.');
+    }
+}
+void dump_data(char *desc, unsigned char *buffer, int length)
+{
+	int i;
+	printf("%s & length is [%d]:\n", desc, length); 
+	for (i=0; i<length; i++) {
+		printf ("[%02X]", 0xff & buffer[i]);
+		if ((i&0xf)==0x7) printf(" - ");
+		if ((i&0xf)==0xf) printf("\n");
+	}
+	printf("\n");
+}
+void get_mac_address_for_node_id(int node_id, char *mac_addr) {
+	int i;
+	int add = node_id;
+	int carry = 0;
+	int mac;
+	for (i=5; i>=0;i--) {
+		mac = (int)based_mac[i];
+		mac += (add + carry);
+		add = 0;
+		if (mac > 255) {
+			carry = 1;
+			mac -= 256;
+		} else {
+			carry = 0;
+		}
+		mac_addr[i] = (char)mac;
+	}
+}
+//return node_id or -1 for error
+int get_node_id_by_mac_address(unsigned char *target_mac_addr) {
+	char mac_addr[ETH_ALEN];
+	int i;
+	for (i=0; i<MAX_SERVER_NODE; i++) {
+		get_mac_address_for_node_id(i, mac_addr);
+		if (0 == memcmp(target_mac_addr, mac_addr, ETH_ALEN))
+			break;
+	}
+	if (i != MAX_SERVER_NODE) {
+//		int j;
+//		printf("mac_address for node[%d]:", i+1);
+//		for (j=0; j<6; j++)
+//			printf("%02x:", 0xff & mac_addr[j]);
+//		printf("\n");
+		return i;
+	} else
+		return -1;
+}
+#if ENABLE_MONOTONIC_SYSCALL
+#include <sys/syscall.h>
+/* Old glibc (< 2.3.4) does not provide this constant. We use syscall
+ * directly so this definition is safe. */
+#ifndef CLOCK_MONOTONIC
+#define CLOCK_MONOTONIC 1
+#endif
+
+unsigned FAST_FUNC monotonic_sec(void)
+{
+	struct timespec ts;
+	get_mono(&ts);
+	return ts.tv_sec;
+}
+
+#else
+
+unsigned monotonic_sec(void)
+{
+	return time(NULL);
+}
+#endif
+//query ip addr for server node w/ mac addr
+//inarp "ethX" "peer mac addr(xx:xx:xx:xx:xx:xx)"
+//inarp daemon to handle inarp packets
+//inarp "ethX" "file for storing node list"
+void InvARPServerTask(
+                                  /** the internal task ID of this task (in) */
+                                  ULONG thread_input
+                                )
+{
+	int fd, ret;
+	/*buffer for ethernet frame*/
+	static unsigned char buffer[ETH_FRAME_LEN]; /* single packets are usually not bigger than 8192 bytes */
+	int send_result = 0;
+    static struct ifreq ifreq_buffer;
+ 
+	/*our MAC address*/
+	static unsigned char src_mac[6];
+	static unsigned char src_ip[4];
+	int ifindex;
+//	int InARP_SERVER;
+
+	if (((fd = socket (AF_PACKET, SOCK_PACKET, htons(ETH_P_ARP)))) == -1) {
+//	if (((fd = socket (AF_PACKET, SOCK_RAW, 0))) == -1) {
+    	printf("socket: [%s]\n", strerror(errno));
+		exit(-1);
+	}
+	//local mac address
+	memset(&ifreq_buffer, 0x00, sizeof(ifreq_buffer));
+	strcpy(ifreq_buffer.ifr_name, "ncsi0");
+	ret = ioctl(fd, SIOCGIFHWADDR, &ifreq_buffer);
+	if (ret == -1) {
+   		printf("ioctl2: [%s]\n", strerror(errno));
+		close(fd);
+		exit(-1);
+	}
+	memcpy(src_mac, ifreq_buffer.ifr_hwaddr.sa_data, ETH_ALEN);
+	show_mac_addr("ncsi0", src_mac);
+    //interface index
+	memset(&ifreq_buffer, 0x00, sizeof(ifreq_buffer));
+	strcpy(ifreq_buffer.ifr_name, "ncsi0");
+	ret = ioctl(fd, SIOCGIFINDEX, &ifreq_buffer);
+	if (ret == -1) {
+   		printf("ioctl4: [%s]\n", strerror(errno));
+		close(fd);
+		exit(-1);
+	}
+	ifindex = ifreq_buffer.ifr_ifindex;
+
+	int length = 0; /*length of the received frame*/
+	static struct ETH_ARP_PACKET *inarp_req = (struct ETH_ARP_PACKET *)buffer; /* single packets are usually not bigger than 8192 bytes */
+	static struct ETH_ARP_PACKET inarp_resp; /* single packets are usually not bigger than 8192 bytes */
+	static struct {
+		unsigned char dest_ip[4];
+		struct timespec update_time;
+	} node[SKU1_MAX_SERVER_NODES];
+	struct timespec current_time;
+	//argv[2]: file name used for storing node ip list
+	//			line format in file: <node_id> <mac_addr> <ip_addr>
+	//get based address via EMS
+	//set socket as async
+//	fcntl(fd, F_SETFL,O_NONBLOCK|FASYNC);
+	//got based address
+	while (1) {
+		//get local ip address
+		memset(&ifreq_buffer, 0x00, sizeof(ifreq_buffer));
+		strcpy(ifreq_buffer.ifr_name, "ncsi0");
+		ret = ioctl(fd, SIOCGIFADDR, &ifreq_buffer);
+		if (ret == -1) {
+//	   		printf("ioctl3: [%s]\n", strerror(errno));
+	   		sleep(1);
+	   		continue;
+		}
+
+	    if (AF_INET == ifreq_buffer.ifr_addr.sa_family) {
+			memcpy(src_ip, &ifreq_buffer.ifr_addr.sa_data[2], 4);
+//			show_ip_addr("local", (unsigned char *)&ifreq_buffer.ifr_addr.sa_data[2]);
+			//show_ip_addr("local", src_ip);
+		} else {
+		    printf("unknown address family [%d]!\n", ifreq_buffer.ifr_addr.sa_family);
+	   		sleep(1);
+	   		continue;
+		}
+
+	    memset((void*)&inarp_resp, 0, sizeof inarp_resp);
+		length = recvfrom(fd, buffer, ETH_ARP_FRAME_LEN, 0, NULL, NULL);
+		if (length == -1) {
+			sleep(1);
+		}
+//		printf("length = %d\r\nfd = %d\r\n", length, fd);
+		current_time.tv_sec = (unsigned)monotonic_sec();
+		if (0 == memcmp(src_mac, inarp_req->eh.h_dest, ETH_ALEN)) {
+			if (ntohs(inarp_req->arp.ar_op) == ARPOP_InREQUEST) {	//get a inverse arp request
+//				printf("[Rsp] InRequest\n");
+				//dump_data("got InARP request packet", buffer, length); 
+				//send inarp response
+				
+				printf("src mac =%02x:%02x:%02x:%02x:%02x:%02x\r\n",
+							inarp_req->arp_data.src_mac[0],
+							inarp_req->arp_data.src_mac[1],
+							inarp_req->arp_data.src_mac[2],
+							inarp_req->arp_data.src_mac[3],
+							inarp_req->arp_data.src_mac[4],
+							inarp_req->arp_data.src_mac[5]
+				);
+				printf("src ip =%d:%d:%d:%d\r\n",
+							inarp_req->arp_data.src_ip[0],
+							inarp_req->arp_data.src_ip[1],
+							inarp_req->arp_data.src_ip[2],
+							inarp_req->arp_data.src_ip[3]
+					);
+				int fd_1;
+				if (((fd_1 = socket (AF_PACKET, SOCK_RAW, 0))) == -1) {
+ 				   	printf("socket: [%s]\n", strerror(errno));
+					exit(-1);
+				}
+				send_result = send_arp_packet(fd_1, ifindex, &inarp_resp, ARPOP_InREPLY,
+									inarp_req->arp_data.dest_mac, src_ip,
+									inarp_req->arp_data.src_mac, inarp_req->arp_data.src_ip);
+				close(fd_1);
+				if (send_result == -1) {
+					printf("[Rsp] sendto: [%s]\n", strerror(errno));
+			   		sleep(1);
+			   		continue;
+				}
+			}
+//			} else if (ntohs(inarp_req->arp.ar_op) == ARPOP_InREPLY) {	//get a InARP Response
+//				int node_id;
+//				printf("[Rsp] InReply\n");
+//				node_id = get_node_id_by_mac_address(inarp_req->arp_data.src_mac);
+//				if (node_id == -1) {
+//					//invalid node
+//					printf("%02x:%02x:%02x:%02x:%02x:%02x does not belong to this rack.",
+//							inarp_req->arp_data.src_mac[0],
+//							inarp_req->arp_data.src_mac[1],
+//							inarp_req->arp_data.src_mac[2],
+//							inarp_req->arp_data.src_mac[3],
+//							inarp_req->arp_data.src_mac[4],
+//							inarp_req->arp_data.src_mac[5]
+//					);
+//				} else {
+					//valid node id
+//					node[node_id].update_time.tv_sec = current_time.tv_sec;
+					//update or remain node's ip
+//					if ((0 != memcmp(node[node_id].dest_ip, inarp_req->arp_data.src_ip, 4))) {
+						//ip address is changed.
+//						static char ipv4_addr[16];
+//						printf("[Rsp] update node[%d] ip @ %u\n", node_id+1, (unsigned)current_time.tv_sec);
+//							show_mac_addr("[Rsp] ", inarp_req->arp_data.src_mac);
+//							show_ip_addr("[Rsp] ", inarp_req->arp_data.src_ip);
+//							memcpy(node[node_id].dest_ip, inarp_req->arp_data.src_ip, 4);
+//						sprintf(ipv4_addr, "%d.%d.%d.%d", 
+//									inarp_req->arp_data.src_ip[0],
+//									inarp_req->arp_data.src_ip[1],
+//									inarp_req->arp_data.src_ip[2],
+//									inarp_req->arp_data.src_ip[3]);
+//						printf("[Rsp] update node[%d] ip @ %u\n", node_id+1, (unsigned)current_time.tv_sec);
+//			}
+		memset(buffer, 0, sizeof(buffer));
+		}
+	}
+	close(fd);
+	return 0;
+}