diff --git a/etc/smartdns/smartdns.conf b/etc/smartdns/smartdns.conf
index 3063439..8cd51bd 100644
--- a/etc/smartdns/smartdns.conf
+++ b/etc/smartdns/smartdns.conf
@@ -76,12 +76,15 @@ log-level info
 # audit-num 2
 
 # remote udp dns server list
-# server [IP]:[PORT] [-blacklist-ip] [-check-edns]
+# server [IP]:[PORT] [-blacklist-ip] [-check-edns] [-check-ttl=[ttl]]
 # default port is 53
+#   -blacklist-ip: filter result with blacklist ip
+#   -check-edns: result must exist edns RR, or discard result.
+#   -check-ttl: Check whether TTL is the corresponding value, or discard result, -check-ttl=0 for auto check TTL.
 # server 8.8.8.8 -blacklist-ip -check-edns
 
 # remote tcp dns server list
-# server-tcp [IP]:[PORT] [-blacklist-ip] [-check-edns]
+# server-tcp [IP]:[PORT] [-blacklist-ip] [-check-edns] 
 # default port is 53
 # server-tcp 8.8.8.8
 
diff --git a/src/dns_client.c b/src/dns_client.c
index 1ccd266..3ca2be2 100644
--- a/src/dns_client.c
+++ b/src/dns_client.c
@@ -109,6 +109,7 @@ struct dns_server_info {
 
 	/* client socket */
 	int fd;
+	int ttl;
 	SSL *ssl;
 	SSL_CTX *ssl_ctx;
 	dns_server_status status;
@@ -225,8 +226,21 @@ int _dns_client_server_exist(struct addrinfo *gai, dns_server_type_t server_type
 	return -1;
 }
 
+void _dns_client_server_update_ttl(struct ping_host_struct *ping_host, const char *host, FAST_PING_RESULT result, struct sockaddr *addr, socklen_t addr_len, int seqno,
+							int ttl, struct timeval *tv, void *userptr)
+{
+	struct dns_server_info *server_info = userptr;
+	if (result != PING_RESULT_RESPONSE || server_info == NULL) {
+		return;
+	}
+
+	double rtt = tv->tv_sec * 1000.0 + tv->tv_usec / 1000.0;
+	tlog(TLOG_INFO, "from %15s: seq=%d ttl=%d time=%.3f\n", host, seqno, ttl, rtt);
+	server_info->ttl = ttl;
+}
+
 /* add dns server information */
-int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_type_t server_type, int result_flag)
+int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_type_t server_type, unsigned int result_flag, int ttl)
 {
 	struct dns_server_info *server_info = NULL;
 
@@ -238,6 +252,11 @@ int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_typ
 	if (server_info == NULL) {
 		goto errout;
 	}
+
+	if (server_type != DNS_SERVER_UDP) {
+		result_flag &= (~DNSSERVER_FLAG_CHECK_TTL);
+	}
+
 	memset(server_info, 0, sizeof(*server_info));
 	server_info->ai_family = gai->ai_family;
 	server_info->ai_addrlen = gai->ai_addrlen;
@@ -245,6 +264,7 @@ int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_typ
 	server_info->fd = 0;
 	server_info->status = DNS_SERVER_STATUS_INIT;
 	server_info->result_flag = result_flag;
+	server_info->ttl = ttl;
 
 	if (gai->ai_addrlen > sizeof(server_info->in6)) {
 		tlog(TLOG_ERROR, "addr len invalid, %d, %zd, %d", gai->ai_addrlen, sizeof(server_info->addr), server_info->ai_family);
@@ -253,13 +273,13 @@ int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_typ
 	memcpy(&server_info->addr, gai->ai_addr, gai->ai_addrlen);
 
 	/* start ping task */
-#if 0
-	server_info->ping_host = fast_ping_start(server_ip, 0, 60000, 1000, NULL, server_info);
-	if (server_info->ping_host == NULL) {
-		tlog(TLOG_ERROR, "start ping failed.");
-		goto errout;
+	if (ttl == 0 && (result_flag & DNSSERVER_FLAG_CHECK_TTL)) {
+		server_info->ping_host = fast_ping_start(server_ip, 0, 60000, 1000, _dns_client_server_update_ttl, server_info);
+		if (server_info->ping_host == NULL) {
+			tlog(TLOG_ERROR, "start ping failed.");
+			goto errout;
+		}
 	}
-#endif
 
 	/* add to list */
 	pthread_mutex_lock(&client.server_list_lock);
@@ -352,7 +372,7 @@ int _dns_client_server_remove(char *server_ip, struct addrinfo *gai, dns_server_
 	return -1;
 }
 
-int _dns_client_server_operate(char *server_ip, int port, dns_server_type_t server_type, int result_flag, int operate)
+int _dns_client_server_operate(char *server_ip, int port, dns_server_type_t server_type, int result_flag, int ttl, int operate)
 {
 	char port_s[8];
 	int sock_type;
@@ -386,7 +406,7 @@ int _dns_client_server_operate(char *server_ip, int port, dns_server_type_t serv
 	}
 
 	if (operate == 0) {
-		ret = _dns_client_server_add(server_ip, gai, server_type, result_flag);
+		ret = _dns_client_server_add(server_ip, gai, server_type, result_flag, ttl);
 		if (ret != 0) {
 			goto errout;
 		}
@@ -405,14 +425,14 @@ errout:
 	return -1;
 }
 
-int dns_add_server(char *server_ip, int port, dns_server_type_t server_type, int result_flag)
+int dns_add_server(char *server_ip, int port, dns_server_type_t server_type, int result_flag, int ttl)
 {
-	return _dns_client_server_operate(server_ip, port, server_type, result_flag, 0);
+	return _dns_client_server_operate(server_ip, port, server_type, result_flag, ttl, 0);
 }
 
 int dns_remove_server(char *server_ip, int port, dns_server_type_t server_type)
 {
-	return _dns_client_server_operate(server_ip, port, server_type, 0, 1);
+	return _dns_client_server_operate(server_ip, port, server_type, 0, 0, 1);
 }
 
 int dns_server_num(void)
@@ -684,6 +704,8 @@ static int _dns_client_create_socket_udp(struct dns_server_info *server_info)
 {
 	int fd = 0;
 	struct epoll_event event;
+	const int on = 1;
+	const int val=255;
 
 	fd = socket(server_info->ai_family, SOCK_DGRAM, 0);
 	if (fd < 0) {
@@ -701,6 +723,8 @@ static int _dns_client_create_socket_udp(struct dns_server_info *server_info)
 
 	server_info->fd = fd;
 	server_info->status = DNS_SERVER_STATUS_CONNECTIONLESS;
+	setsockopt(server_info->fd, IPPROTO_IP, IP_RECVTTL, &on, sizeof(on));
+	setsockopt(server_info->fd, SOL_IP, IP_TTL, &val, sizeof(val));
 
 	return 0;
 errout:
@@ -857,15 +881,45 @@ static int _dns_client_process_udp(struct dns_server_info *server_info, struct e
 	struct sockaddr_storage from;
 	socklen_t from_len = sizeof(from);
 	char from_host[DNS_MAX_CNAME_LEN];
+	struct msghdr msg;
+	struct iovec iov;
+	char ans_data[4096];
+	int ttl = 0;
+	struct cmsghdr *cmsg;
 
-	/* receive from udp */
-	len = recvfrom(server_info->fd, inpacket, sizeof(inpacket), 0, (struct sockaddr *)&from, (socklen_t *)&from_len);
+	memset(&msg, 0, sizeof(msg));
+	iov.iov_base = (char *)inpacket;
+	iov.iov_len = sizeof(inpacket);
+	msg.msg_name = &from;
+	msg.msg_namelen = sizeof(from);
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = ans_data;
+	msg.msg_controllen = sizeof(ans_data);
+
+	len = recvmsg(server_info->fd, &msg, MSG_DONTWAIT);
 	if (len < 0) {
 		tlog(TLOG_ERROR, "recvfrom failed, %s\n", strerror(errno));
 		return -1;
 	}
+	from_len = msg.msg_namelen;
 
-	tlog(TLOG_DEBUG, "recv udp, from %s", gethost_by_addr(from_host, (struct sockaddr *)&from, from_len));
+	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+		if (cmsg->cmsg_level == SOL_IP
+			&& cmsg->cmsg_type == IP_TTL
+		) {
+			uint8_t * ttlPtr = (uint8_t *)CMSG_DATA(cmsg);
+			ttl = *ttlPtr;
+			break;
+		}
+	}
+
+	tlog(TLOG_DEBUG, "recv udp, from %s, ttl: %d", gethost_by_addr(from_host, (struct sockaddr *)&from, from_len), ttl);
+
+	if ((ttl != server_info->ttl) && (server_info->result_flag & DNSSERVER_FLAG_CHECK_TTL)) {
+		tlog(TLOG_DEBUG, "TTL mismatch, from:%d, local %d, discard result", ttl, server_info->ttl);
+		return 0;
+	}
 
 	time(&server_info->last_recv);
 	if (_dns_client_recv(server_info, inpacket, len, (struct sockaddr *)&from, from_len) != 0) {
diff --git a/src/dns_client.h b/src/dns_client.h
index 651a11d..313bfe5 100644
--- a/src/dns_client.h
+++ b/src/dns_client.h
@@ -18,6 +18,7 @@ typedef enum dns_result_type {
 
 #define DNSSERVER_FLAG_BLACKLIST_IP (0x1 << 0)
 #define DNSSERVER_FLAG_CHECK_EDNS (0x1 << 1)
+#define DNSSERVER_FLAG_CHECK_TTL (0x1 << 2)
 
 int dns_client_init(void);
 
@@ -32,7 +33,7 @@ int dns_client_query(char *domain, int qtype, dns_client_callback callback, void
 void dns_client_exit(void);
 
 /* add remote dns server */
-int dns_add_server(char *server_ip, int port, dns_server_type_t server_type, int result_flag);
+int dns_add_server(char *server_ip, int port, dns_server_type_t server_type, int result_flag, int ttl);
 
 /* remove remote dns server */
 int dns_remove_server(char *server_ip, int port, dns_server_type_t server_type);
diff --git a/src/dns_conf.c b/src/dns_conf.c
index 207ded0..2217d81 100644
--- a/src/dns_conf.c
+++ b/src/dns_conf.c
@@ -55,10 +55,12 @@ int config_server(int argc, char *argv[], dns_server_type_t type, int default_po
 	char *ip = NULL;
 	int opt = 0;
 	int result_flag = 0;
+	int ttl = 0;
 	/* clang-format off */
 	static struct option long_options[] = {
 		{"blacklist-ip", 0, 0, 'b'},
 		{"check-edns", 0, 0, 'e'},
+		{"check-ttl", required_argument, 0, 't'},
 		{0, 0, 0, 0}
 	};
 	/* clang-format on */
@@ -84,6 +86,18 @@ int config_server(int argc, char *argv[], dns_server_type_t type, int default_po
 			result_flag |= DNSSERVER_FLAG_CHECK_EDNS;
 			break;
 		}
+		case 't': {
+			if (DNS_SERVER_UDP != type) {
+				break;
+			}
+
+			ttl = atoi(optarg);
+			if (ttl < 0 || ttl > 255) {
+				tlog(TLOG_ERROR, "ttl value is invalid.");
+				return -1;
+			}
+			result_flag |= DNSSERVER_FLAG_CHECK_TTL;
+		}
 		}
 	}
 
@@ -106,8 +120,9 @@ int config_server(int argc, char *argv[], dns_server_type_t type, int default_po
 	server->type = type;
 	server->port = port;
 	server->result_flag = result_flag;
+	server->ttl = ttl;
 	dns_conf_server_num++;
-	tlog(TLOG_DEBUG, "add server %s, flag: %X", ip, result_flag);
+	tlog(TLOG_DEBUG, "add server %s, flag: %X, ttl: %d", ip, result_flag, ttl);
 
 	return 0;
 }
diff --git a/src/dns_conf.h b/src/dns_conf.h
index 740d9d2..1798c3f 100644
--- a/src/dns_conf.h
+++ b/src/dns_conf.h
@@ -53,6 +53,7 @@ struct dns_servers {
 	char server[DNS_MAX_IPLEN];
 	unsigned short port;
 	unsigned int result_flag;
+	int ttl;
 	dns_server_type_t type;
 };
 
diff --git a/src/dns_server.c b/src/dns_server.c
index 9f9fb98..42ce90b 100644
--- a/src/dns_server.c
+++ b/src/dns_server.c
@@ -650,7 +650,7 @@ void _dns_server_request_get(struct dns_request *request)
 }
 
 void _dns_server_ping_result(struct ping_host_struct *ping_host, const char *host, FAST_PING_RESULT result, struct sockaddr *addr, socklen_t addr_len,
-							 int seqno, struct timeval *tv, void *userptr)
+							 int seqno, int ttl, struct timeval *tv, void *userptr)
 {
 	struct dns_request *request = userptr;
 	int may_complete = 0;
diff --git a/src/fast_ping.c b/src/fast_ping.c
index d9562c7..30fbbab 100644
--- a/src/fast_ping.c
+++ b/src/fast_ping.c
@@ -56,6 +56,7 @@ struct fast_ping_packet {
 		struct icmp icmp;
 		struct icmp6_hdr icmp6;
 	};
+	unsigned int ttl;
 	struct fast_ping_packet_msg msg;
 };
 
@@ -72,6 +73,7 @@ struct ping_host_struct {
 
 	int fd;
 	unsigned int seq;
+	int ttl;
 	struct timeval last;
 	int interval;
 	int timeout;
@@ -267,7 +269,7 @@ static void _fast_ping_host_put(struct ping_host_struct *ping_host)
 		tv.tv_sec = 0;
 		tv.tv_usec = 0;
 
-		ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_END, &ping_host->addr, ping_host->addr_len, ping_host->seq, &tv, ping_host->userptr);
+		ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_END, &ping_host->addr, ping_host->addr_len, ping_host->seq, ping_host->ttl, &tv, ping_host->userptr);
 	}
 
 	tlog(TLOG_DEBUG, "ping %p end", ping_host);
@@ -294,7 +296,7 @@ static void _fast_ping_host_remove(struct ping_host_struct *ping_host)
 		tv.tv_sec = 0;
 		tv.tv_usec = 0;
 
-		ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_END, &ping_host->addr, ping_host->addr_len, ping_host->seq, &tv, ping_host->userptr);
+		ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_END, &ping_host->addr, ping_host->addr_len, ping_host->seq, ping_host->ttl, &tv, ping_host->userptr);
 	}
 
 	_fast_ping_host_put(ping_host);
@@ -469,6 +471,8 @@ static int _fast_ping_create_icmp_sock(FAST_PING_TYPE type)
 	struct epoll_event event;
 	int buffsize = 64 * 1024;
 	socklen_t optlen = sizeof(buffsize);
+	const int val=255;
+	const int on = 1;
 
 	switch (type) {
 	case FAST_PING_ICMP:
@@ -487,6 +491,9 @@ static int _fast_ping_create_icmp_sock(FAST_PING_TYPE type)
 			goto errout;
 		}
 		_fast_ping_install_filter_v6(fd);
+		setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, sizeof(on));
+		setsockopt(fd, IPPROTO_IPV6, IPV6_2292HOPLIMIT, &on, sizeof(on));
+		setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &on, sizeof(on));
 		icmp_host = &ping.icmp6_host;
 		break;
 	default:
@@ -495,6 +502,7 @@ static int _fast_ping_create_icmp_sock(FAST_PING_TYPE type)
 
 	setsockopt(fd, SOL_SOCKET, SO_SNDBUF, (const char *)&buffsize, optlen);
 	setsockopt(fd, SOL_SOCKET, SO_RCVBUF, (const char *)&buffsize, optlen);
+	setsockopt(fd, SOL_IP, IP_TTL, &val, sizeof(val));
 
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN;
@@ -552,11 +560,11 @@ errout:
 }
 
 void fast_ping_print_result(struct ping_host_struct *ping_host, const char *host, FAST_PING_RESULT result, struct sockaddr *addr, socklen_t addr_len, int seqno,
-							struct timeval *tv, void *userptr)
+							int ttl, struct timeval *tv, void *userptr)
 {
 	if (result == PING_RESULT_RESPONSE) {
 		double rtt = tv->tv_sec * 1000.0 + tv->tv_usec / 1000.0;
-		tlog(TLOG_INFO, "from %15s: seq=%d time=%.3f\n", host, seqno, rtt);
+		tlog(TLOG_INFO, "from %15s: seq=%d ttl=%d time=%.3f\n", host, seqno, ttl, rtt);
 	} else if (result == PING_RESULT_TIMEOUT) {
 		tlog(TLOG_INFO, "from %15s: seq=%d timeout\n", host, seqno);
 	} else if (result == PING_RESULT_END) {
@@ -694,6 +702,10 @@ errout_remove:
 
 int fast_ping_stop(struct ping_host_struct *ping_host)
 {
+	if (ping_host == NULL) {
+		return 0;
+	}
+	
 	atomic_inc_return(&ping_host->notified);
 	_fast_ping_host_remove(ping_host);
 	_fast_ping_host_put(ping_host);
@@ -709,12 +721,29 @@ static void tv_sub(struct timeval *out, struct timeval *in)
 	out->tv_sec -= in->tv_sec;
 }
 
-static struct fast_ping_packet *_fast_ping_icmp6_packet(struct ping_host_struct *ping_host, u_char *packet_data, int data_len)
+static struct fast_ping_packet *_fast_ping_icmp6_packet(struct ping_host_struct *ping_host, struct msghdr *msg, u_char *packet_data, int data_len)
 {
 	int icmp_len;
 	struct fast_ping_packet *packet = (struct fast_ping_packet *)packet_data;
 	struct icmp6_hdr *icmp6 = &packet->icmp6;
+	struct cmsghdr *c;
+	int hops = 0;
 
+	for (c = CMSG_FIRSTHDR(msg); c; c = CMSG_NXTHDR(msg, c)) {
+		if (c->cmsg_level != IPPROTO_IPV6)
+			continue;
+		switch(c->cmsg_type) {
+		case IPV6_HOPLIMIT:
+#ifdef IPV6_2292HOPLIMIT
+		case IPV6_2292HOPLIMIT:
+#endif
+			if (c->cmsg_len < CMSG_LEN(sizeof(int)))
+				continue;
+			memcpy(&hops, CMSG_DATA(c), sizeof(hops));
+		}
+	}
+
+	packet->ttl = hops;
 	if (icmp6->icmp6_type != ICMP6_ECHO_REPLY) {
 		tlog(TLOG_DEBUG, "icmp6 type faild, %d:%d", icmp6->icmp6_type, ICMP6_ECHO_REPLY);
 		return NULL;
@@ -734,7 +763,7 @@ static struct fast_ping_packet *_fast_ping_icmp6_packet(struct ping_host_struct
 	return packet;
 }
 
-static struct fast_ping_packet *_fast_ping_icmp_packet(struct ping_host_struct *ping_host, u_char *packet_data, int data_len)
+static struct fast_ping_packet *_fast_ping_icmp_packet(struct ping_host_struct *ping_host, struct msghdr *msg, u_char *packet_data, int data_len)
 {
 	struct ip *ip = (struct ip *)packet_data;
 	struct fast_ping_packet *packet;
@@ -751,6 +780,7 @@ static struct fast_ping_packet *_fast_ping_icmp_packet(struct ping_host_struct *
 	packet = (struct fast_ping_packet *)(packet_data + hlen);
 	icmp = &packet->icmp;
 	icmp_len = data_len - hlen;
+	packet->ttl = ip->ip_ttl;
 
 	if (icmp_len < 16) {
 		tlog(TLOG_ERROR, "length is invalid, %d", icmp_len);
@@ -770,17 +800,17 @@ static struct fast_ping_packet *_fast_ping_icmp_packet(struct ping_host_struct *
 	return packet;
 }
 
-struct fast_ping_packet *_fast_ping_recv_packet(struct ping_host_struct *ping_host, u_char *inpacket, int len, struct timeval *tvrecv)
+struct fast_ping_packet *_fast_ping_recv_packet(struct ping_host_struct *ping_host, struct msghdr *msg, u_char *inpacket, int len, struct timeval *tvrecv)
 {
 	struct fast_ping_packet *packet = NULL;
 
 	if (ping_host->type == FAST_PING_ICMP6) {
-		packet = _fast_ping_icmp6_packet(ping_host, inpacket, len);
+		packet = _fast_ping_icmp6_packet(ping_host, msg, inpacket, len);
 		if (packet == NULL) {
 			goto errout;
 		}
 	} else if (ping_host->type == FAST_PING_ICMP) {
-		packet = _fast_ping_icmp_packet(ping_host, inpacket, len);
+		packet = _fast_ping_icmp_packet(ping_host, msg, inpacket, len);
 		if (packet == NULL) {
 			goto errout;
 		}
@@ -808,14 +838,28 @@ static int _fast_ping_process_icmp(struct ping_host_struct *ping_host, struct ti
 	unsigned int sid;
 	unsigned int seq;
 	unsigned int cookie;
+	struct msghdr msg;
+	struct iovec iov;
+	char ans_data[4096];
 
-	len = recvfrom(ping_host->fd, inpacket, sizeof(inpacket), 0, (struct sockaddr *)&from, (socklen_t *)&from_len);
+	memset(&msg, 0, sizeof(msg));
+	iov.iov_base = (char *)inpacket;
+	iov.iov_len = sizeof(inpacket);
+	msg.msg_name = &from;
+	msg.msg_namelen = sizeof(from);
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = ans_data;
+	msg.msg_controllen = sizeof(ans_data);
+
+	len = recvmsg(ping_host->fd, &msg, MSG_DONTWAIT);
 	if (len < 0) {
 		tlog(TLOG_ERROR, "recvfrom failed, %s\n", strerror(errno));
 		goto errout;
 	}
 
-	packet = _fast_ping_recv_packet(ping_host, inpacket, len, now);
+	from_len = msg.msg_namelen;
+	packet = _fast_ping_recv_packet(ping_host, &msg, inpacket, len, now);
 	if (packet == NULL) {
 		char name[PING_MAX_HOSTLEN];
 		tlog(TLOG_DEBUG, "recv ping packet from %s failed.", gethost_by_addr(name, (struct sockaddr *)&from, from_len));
@@ -848,10 +892,11 @@ static int _fast_ping_process_icmp(struct ping_host_struct *ping_host, struct ti
 		return -1;
 	}
 
+	recv_ping_host->ttl = packet->ttl;
 	tv_sub(&tvresult, tvsend);
 	if (recv_ping_host->ping_callback) {
 		recv_ping_host->ping_callback(recv_ping_host, recv_ping_host->host, PING_RESULT_RESPONSE, &recv_ping_host->addr, recv_ping_host->addr_len,
-									  recv_ping_host->seq, &tvresult, recv_ping_host->userptr);
+									  recv_ping_host->seq, recv_ping_host->ttl, &tvresult, recv_ping_host->userptr);
 	}
 
 	recv_ping_host->send = 0;
@@ -882,8 +927,8 @@ static int _fast_ping_process_tcp(struct ping_host_struct *ping_host, struct epo
 	}
 	tv_sub(&tvresult, tvsend);
 	if (ping_host->ping_callback) {
-		ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_RESPONSE, &ping_host->addr, ping_host->addr_len, ping_host->seq, &tvresult,
-								 ping_host->userptr);
+		ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_RESPONSE, &ping_host->addr, ping_host->addr_len, ping_host->seq, 
+			ping_host->ttl, &tvresult, ping_host->userptr);
 	}
 
 	ping_host->send = 0;
@@ -984,8 +1029,8 @@ static void _fast_ping_period_run(void)
 		tv_sub(&interval, &ping_host->last);
 		millisecond = interval.tv_sec * 1000 + interval.tv_usec / 1000;
 		if (millisecond >= ping_host->timeout && ping_host->send == 1) {
-			ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_TIMEOUT, &ping_host->addr, ping_host->addr_len, ping_host->seq, &interval,
-									 ping_host->userptr);
+			ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_TIMEOUT, &ping_host->addr, ping_host->addr_len, ping_host->seq, 
+					ping_host->ttl, &interval, ping_host->userptr);
 			ping_host->send = 0;
 		}
 
diff --git a/src/fast_ping.h b/src/fast_ping.h
index 5edfde2..62b221c 100644
--- a/src/fast_ping.h
+++ b/src/fast_ping.h
@@ -22,7 +22,7 @@ typedef enum {
 } FAST_PING_RESULT;
 
 struct ping_host_struct;
-typedef void (*fast_ping_result)(struct ping_host_struct *ping_host, const char *host, FAST_PING_RESULT result, struct sockaddr *addr, socklen_t addr_len, int seqno, struct timeval *tv, void *userptr);
+typedef void (*fast_ping_result)(struct ping_host_struct *ping_host, const char *host, FAST_PING_RESULT result, struct sockaddr *addr, socklen_t addr_len, int seqno, int ttl, struct timeval *tv, void *userptr);
 
 /* start ping */
 struct ping_host_struct *fast_ping_start(const char *host, int count, int interval, int timeout, fast_ping_result ping_callback, void *userptr);
diff --git a/src/smartdns.c b/src/smartdns.c
index d3da0b6..430eb1e 100644
--- a/src/smartdns.c
+++ b/src/smartdns.c
@@ -124,7 +124,8 @@ int smartdns_add_servers(void)
 	int i = 0;
 	int ret = 0;
 	for (i = 0; i < dns_conf_server_num; i++) {
-		ret = dns_add_server(dns_conf_servers[i].server, dns_conf_servers[i].port, dns_conf_servers[i].type, dns_conf_servers[i].result_flag);
+		ret = dns_add_server(dns_conf_servers[i].server, dns_conf_servers[i].port, dns_conf_servers[i].type, dns_conf_servers[i].result_flag, 
+			dns_conf_servers[i].ttl);
 		if (ret != 0) {
 			tlog(TLOG_ERROR, "add server failed, %s:%d", dns_conf_servers[i].server, dns_conf_servers[i].port);
 			return -1;