diff --git a/src/dns_client.c b/src/dns_client.c
index c8f584c..0c93a14 100644
--- a/src/dns_client.c
+++ b/src/dns_client.c
@@ -60,6 +60,8 @@
 #define DNS_TCP_CONNECT_TIMEOUT (5)
 #define DNS_QUERY_TIMEOUT (500)
 #define DNS_QUERY_RETRY (3)
+#define SOCKET_PRIORITY (6)
+#define SOCKET_IP_TOS (IPTOS_LOWDELAY | IPTOS_RELIABILITY)
 
 #ifndef TCP_FASTOPEN_CONNECT
 #define TCP_FASTOPEN_CONNECT 30
@@ -1312,6 +1314,8 @@ static int _dns_client_create_socket_udp(struct dns_server_info *server_info)
 	struct epoll_event event;
 	const int on = 1;
 	const int val = 255;
+	const int priority = SOCKET_PRIORITY;
+	const int ip_tos = SOCKET_IP_TOS;
 
 	fd = socket(server_info->ai_family, SOCK_DGRAM, 0);
 	if (fd < 0) {
@@ -1331,6 +1335,8 @@ static int _dns_client_create_socket_udp(struct dns_server_info *server_info)
 	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));
+	setsockopt(server_info->fd, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority));
+	setsockopt(server_info->fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));
 	if (server_info->ai_family == AF_INET6) {
 		/* for recving ip ttl value */
 		setsockopt(server_info->fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, sizeof(on));
@@ -1352,6 +1358,8 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)
 	int fd = 0;
 	struct epoll_event event;
 	int yes = 1;
+	const int priority = SOCKET_PRIORITY;
+	const int ip_tos = SOCKET_IP_TOS;
 
 	fd = socket(server_info->ai_family, SOCK_STREAM, 0);
 	if (fd < 0) {
@@ -1370,6 +1378,8 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)
 	}
 
 	setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes));
+	setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority));
+	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));
 
 	if (connect(fd, (struct sockaddr *)&server_info->addr, server_info->ai_addrlen) != 0) {
 		if (errno != EINPROGRESS) {
@@ -1406,6 +1416,8 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 	struct epoll_event event;
 	SSL *ssl = NULL;
 	int yes = 1;
+	const int priority = SOCKET_PRIORITY;
+	const int ip_tos = SOCKET_IP_TOS;
 
 	if (server_info->ssl_ctx == NULL) {
 		tlog(TLOG_ERROR, "create ssl ctx failed.");
@@ -1435,6 +1447,8 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 
 	// ? this cause ssl crash ?
 	// setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes));
+	setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority));
+	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));
 
 	if (connect(fd, (struct sockaddr *)&server_info->addr, server_info->ai_addrlen) != 0) {
 		if (errno != EINPROGRESS) {
diff --git a/src/dns_server.c b/src/dns_server.c
index bab1fc5..100bdce 100644
--- a/src/dns_server.c
+++ b/src/dns_server.c
@@ -38,7 +38,9 @@
 #include <string.h>
 #include <sys/epoll.h>
 #include <sys/socket.h>
-#include <sys/types.h> /* See NOTES */
+#include <sys/types.h>
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
 
 #define DNS_MAX_EVENTS 256
 #define DNS_SERVER_TMOUT_TTL (5 * 60)
@@ -47,6 +49,8 @@
 #define DNS_PING_TIMEOUT (DNS_REQUEST_MAX_TIMEOUT)
 #define DNS_TCPPING_START (300)
 #define DNS_PING_SECOND_TIMEOUT (DNS_REQUEST_MAX_TIMEOUT - DNS_TCPPING_START)
+#define SOCKET_IP_TOS (IPTOS_LOWDELAY | IPTOS_RELIABILITY)
+#define SOCKET_PRIORITY (6)
 
 #define RECV_ERROR_AGAIN 1
 #define RECV_ERROR_OK 0
@@ -2832,6 +2836,9 @@ static int _dns_create_socket(const char *host_ip, int type)
 	int port;
 	char *host = NULL;
 	int optval = 1;
+	int yes = 1;
+	const int priority = SOCKET_PRIORITY;
+	const int ip_tos = SOCKET_IP_TOS;
 
 	if (parse_ip(host_ip, ip, &port) == 0) {
 		host = ip;
@@ -2859,10 +2866,13 @@ static int _dns_create_socket(const char *host_ip, int type)
 			tlog(TLOG_ERROR, "set socket opt failed.");
 			goto errout;
 		}
+		setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes));
 	} else {
 		setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &optval, sizeof(optval));
 		setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &optval, sizeof(optval));
 	}
+	setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority));
+	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));
 
 	if (bind(fd, gai->ai_addr, gai->ai_addrlen) != 0) {
 		tlog(TLOG_ERROR, "bind service failed, %s\n", strerror(errno));
diff --git a/src/fast_ping.c b/src/fast_ping.c
index 5be3673..19200b1 100644
--- a/src/fast_ping.c
+++ b/src/fast_ping.c
@@ -46,6 +46,7 @@
 #define ICMP_INPACKET_SIZE 1024
 #define IPV4_ADDR_LEN 4
 #define IPV6_ADDR_LEN 16
+#define SOCKET_PRIORITY (6)
 
 #ifndef ICMP_FILTER
 #define ICMP_FILTER 1
@@ -550,6 +551,9 @@ static int _fast_ping_sendping_tcp(struct ping_host_struct *ping_host)
 	struct epoll_event event;
 	int flags;
 	int fd = -1;
+	int yes = 1;
+	const int priority = SOCKET_PRIORITY;
+	const int ip_tos = IP_TOS;
 
 	_fast_ping_close_host_sock(ping_host);
 
@@ -560,6 +564,9 @@ static int _fast_ping_sendping_tcp(struct ping_host_struct *ping_host)
 
 	flags = fcntl(fd, F_GETFL, 0);
 	fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+	setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes));
+	setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority));
+	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));
 
 	ping_host->seq++;
 	if (connect(fd, (struct sockaddr *)&ping_host->addr, ping_host->addr_len) != 0) {
@@ -635,6 +642,7 @@ static int _fast_ping_create_icmp_sock(FAST_PING_TYPE type)
 	socklen_t optlen = sizeof(buffsize);
 	const int val = 255;
 	const int on = 1;
+	const int ip_tos = (IPTOS_LOWDELAY | IPTOS_RELIABILITY);
 
 	switch (type) {
 	case FAST_PING_ICMP:
@@ -669,6 +677,7 @@ 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));
+	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));
 
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN;
@@ -732,6 +741,7 @@ static int _fast_ping_create_udp_sock(FAST_PING_TYPE type)
 	struct epoll_event event;
 	const int val = 255;
 	const int on = 1;
+	const int ip_tos = (IPTOS_LOWDELAY | IPTOS_RELIABILITY);
 
 	switch (type) {
 	case FAST_PING_UDP:
@@ -763,6 +773,7 @@ static int _fast_ping_create_udp_sock(FAST_PING_TYPE type)
 
 	setsockopt(fd, SOL_IP, IP_TTL, &val, sizeof(val));
 	setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &on, sizeof(on));
+	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));
 
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN;