diff --git a/package/luci-compat/files/luci/i18n/smartdns.zh-cn.po b/package/luci-compat/files/luci/i18n/smartdns.zh-cn.po
index 0c38dd9..0c5b3d8 100644
--- a/package/luci-compat/files/luci/i18n/smartdns.zh-cn.po
+++ b/package/luci-compat/files/luci/i18n/smartdns.zh-cn.po
@@ -269,6 +269,11 @@ msgstr "SmartDNS官方网站"
 msgid "Smartdns local server port"
 msgstr "SmartDNS本地服务端口"
 
+msgid ""
+"Smartdns local server port, smartdns will be automatically set as main dns "
+"when the port is 53."
+msgstr "SmartDNS本地服务端口，当端口号设置为53时，smartdns将会自动配置为主dns。"
+
 msgid "Smartdns server name"
 msgstr "SmartDNS的服务器名称，默认为smartdns，留空为主机名"
 
diff --git a/package/luci-compat/files/luci/model/cbi/smartdns/smartdns.lua b/package/luci-compat/files/luci/model/cbi/smartdns/smartdns.lua
index 96a1505..6d7b0bb 100644
--- a/package/luci-compat/files/luci/model/cbi/smartdns/smartdns.lua
+++ b/package/luci-compat/files/luci/model/cbi/smartdns/smartdns.lua
@@ -45,7 +45,8 @@ o.datatype    = "hostname"
 o.rempty      = false
 
 ---- Port
-o = s:taboption("settings", Value, "port", translate("Local Port"), translate("Smartdns local server port"))
+o = s:taboption("settings", Value, "port", translate("Local Port"), 
+    translate("Smartdns local server port, smartdns will be automatically set as main dns when the port is 53."))
 o.placeholder = 53
 o.default     = 53
 o.datatype    = "port"
diff --git a/package/luci/files/luci/i18n/smartdns.zh-cn.po b/package/luci/files/luci/i18n/smartdns.zh-cn.po
index 0c38dd9..0c5b3d8 100644
--- a/package/luci/files/luci/i18n/smartdns.zh-cn.po
+++ b/package/luci/files/luci/i18n/smartdns.zh-cn.po
@@ -269,6 +269,11 @@ msgstr "SmartDNS官方网站"
 msgid "Smartdns local server port"
 msgstr "SmartDNS本地服务端口"
 
+msgid ""
+"Smartdns local server port, smartdns will be automatically set as main dns "
+"when the port is 53."
+msgstr "SmartDNS本地服务端口，当端口号设置为53时，smartdns将会自动配置为主dns。"
+
 msgid "Smartdns server name"
 msgstr "SmartDNS的服务器名称，默认为smartdns，留空为主机名"
 
diff --git a/package/luci/files/root/www/luci-static/resources/view/smartdns/smartdns.js b/package/luci/files/root/www/luci-static/resources/view/smartdns/smartdns.js
index 2fd42b9..9796beb 100644
--- a/package/luci/files/root/www/luci-static/resources/view/smartdns/smartdns.js
+++ b/package/luci/files/root/www/luci-static/resources/view/smartdns/smartdns.js
@@ -122,7 +122,8 @@
 		 o.rempty = false;
  
 		 // Port;
-		 o = s.taboption("settings", form.Value, "port", _("Local Port"), _("Smartdns local server port"));
+		 o = s.taboption("settings", form.Value, "port", _("Local Port"), 
+		 	_("Smartdns local server port, smartdns will be automatically set as main dns when the port is 53."));
 		 o.placeholder = 53;
 		 o.default = 53;
 		 o.datatype = "port";
diff --git a/package/openwrt/files/etc/init.d/smartdns b/package/openwrt/files/etc/init.d/smartdns
index 7abd729..ae629ff 100644
--- a/package/openwrt/files/etc/init.d/smartdns
+++ b/package/openwrt/files/etc/init.d/smartdns
@@ -31,22 +31,21 @@ CUSTOM_CONF="$SMARTDNS_CONF_DIR/custom.conf"
 SMARTDNS_CONF_TMP="${SMARTDNS_CONF}.tmp"
 COREDUMP="0"
 RESPAWN="1"
-UPSTREAM_SERVER_NUM=0
 
 set_forward_dnsmasq()
 {
 	local PORT="$1"
 	addr="127.0.0.1#$PORT"
-	OLD_SERVER="$(uci get dhcp.@dnsmasq[0].server 2>/dev/null)"
+	OLD_SERVER="$(uci -q get dhcp.@dnsmasq[0].server)"
 	if echo "$OLD_SERVER" | grep "^$addr" >/dev/null 2>&1; then
 		return
 	fi
 
-	uci delete dhcp.@dnsmasq[0].server 2>/dev/null
-	uci add_list dhcp.@dnsmasq[0].server="$addr"
-	uci set dhcp.@dnsmasq[0].noresolv=1
-	uci set dhcp.@dnsmasq[0].rebind_protection=0
-	uci set dhcp.@dnsmasq[0].domainneeded=0
+	uci -q delete dhcp.@dnsmasq[0].server
+	uci -q add_list dhcp.@dnsmasq[0].server="$addr"
+	uci -q set dhcp.@dnsmasq[0].noresolv=1
+	uci -q set dhcp.@dnsmasq[0].rebind_protection=0
+	uci -q set dhcp.@dnsmasq[0].domainneeded=0
 	uci commit dhcp
 	/etc/init.d/dnsmasq restart
 }
@@ -55,15 +54,15 @@ stop_forward_dnsmasq()
 {
 	local OLD_PORT="$1"
 	addr="127.0.0.1#$OLD_PORT"
-	OLD_SERVER="$(uci get dhcp.@dnsmasq[0].server 2>/dev/null)"
+	OLD_SERVER="$(uci -q get dhcp.@dnsmasq[0].server)"
 	if ! echo "$OLD_SERVER" | grep "^$addr" >/dev/null 2>&1; then
 		return
 	fi
 	
-	uci delete dhcp.@dnsmasq[0].server  2>/dev/null
-	uci delete dhcp.@dnsmasq[0].noresolv 2>/dev/null
-	uci set dhcp.@dnsmasq[0].rebind_protection=1
-	uci set dhcp.@dnsmasq[0].domainneeded=1
+	uci -q delete dhcp.@dnsmasq[0].server
+	uci -q delete dhcp.@dnsmasq[0].noresolv
+	uci -q set dhcp.@dnsmasq[0].rebind_protection=1
+	uci -q set dhcp.@dnsmasq[0].domainneeded=1
 	uci commit dhcp
 	/etc/init.d/dnsmasq restart
 }
@@ -85,17 +84,26 @@ stop_set_dnsmasq()
 	[ "$port" == "$old_port" ] || stop_forward_dnsmasq "$old_port"
 }
 
-
 set_main_dns()
 {
-	uci set dhcp.@dnsmasq[0].port=0
+	local hostip
+	hostip="$(uci -q get network.lan.ipaddr)"
+	
+	if [ -z "$hostip" ]; then
+		return
+	fi
+
+	uci -q set dhcp.@dnsmasq[0].port=0
+	uci -q set dhcp.lan.dhcp_option="6,$hostip"
+
 	uci commit dhcp
 	/etc/init.d/dnsmasq restart
 }
 
 stop_main_dns()
 {
-	uci delete dhcp.@dnsmasq[0].port 2>/dev/null
+	uci -q delete dhcp.@dnsmasq[0].port
+	uci -q delete dhcp.lan.dhcp_option
 	uci commit dhcp
 	/etc/init.d/dnsmasq restart
 }
@@ -119,7 +127,6 @@ clear_iptable()
 		ip6tables -t nat -D PREROUTING -p udp -d "$IP" --dport 53 -j REDIRECT --to-ports "$OLD_PORT" >/dev/null 2>&1
 		ip6tables -t nat -D PREROUTING -p tcp -d "$IP" --dport 53 -j REDIRECT --to-ports "$OLD_PORT" >/dev/null 2>&1
 	done
-
 }
 
 service_triggers() {
@@ -208,21 +215,6 @@ load_server()
 	[ "$type" = "https" ] && DNS_ADDRESS="$ip"
 
 	conf_append "$SERVER" "$DNS_ADDRESS $ADDITIONAL_ARGS $addition_arg"
-	((UPSTREAM_SERVER_NUM=UPSTREAM_SERVER_NUM+1))
-}
-
-load_resolv_conf()
-{
-	resolve_file="$(uci get dhcp.@dnsmasq[0].resolvfile 2>/dev/null)"
-	[ -z "$dhcp.@dnsmasq[0].resolvfile" ] && return 1
-	[ -e "$resolve_file" ] || return 1
-
-	while read line
-	do
-		IP="$(echo "$line" | grep "nameserver " | awk '{print $2}')"
-		[ -z "$IP" ] && continue
-		conf_append "server" "$IP"
-	done < $resolve_file
 }
 
 load_second_server()
@@ -279,8 +271,13 @@ load_service()
 {
 	local section="$1"
 	args=""
-	dnsmasq_lease_file="$(uci get dhcp.@dnsmasq[0].leasefile 2>/dev/null)"
-	dnsmasq_port="$(uci get dhcp.@dnsmasq[0].port 2>/dev/null)"
+	dnsmasq_lease_file="$(uci -q get dhcp.@dnsmasq[0].leasefile)"
+	dnsmasq_port="$(uci -q get dhcp.@dnsmasq[0].port)"
+	resolve_file="$(uci -q get dhcp.@dnsmasq[0].resolvfile)"
+	[ -z "$dnsmasq_lease_file" ] && dnsmasq_lease_file="/tmp/dhcp.leases"
+	[ -z "$dnsmasq_port" ] && dnsmasq_port="53"
+	[ -z "$resolve_file" ] && resolve_file="/tmp/resolv.conf.d/resolv.conf.auto"
+
 	qtype_soa_list=""
 
 	mkdir -p $SMARTDNS_VAR_CONF_DIR
@@ -319,7 +316,7 @@ load_service()
 	config_get force_https_soa "$section" "force_https_soa" "0"
 	[ "$force_https_soa" = "1" ] && qtype_soa_list="$qtype_soa_list 65"
 
-	config_get auto_set_dnsmasq "$section" "auto_set_dnsmasq" ""
+	config_get auto_set_dnsmasq "$section" "auto_set_dnsmasq" "0"
 
 	config_get rr_ttl "$section" "rr_ttl" ""
 	[ -z "$rr_ttl" ] || conf_append "rr-ttl" "$rr_ttl"
@@ -349,6 +346,7 @@ load_service()
 	config_get old_port "$section" "old_port" "0"
 
 	[ -z "$qtype_soa_list" ] || conf_append "force-qtype-SOA" "$qtype_soa_list"
+	[ -e "$resolve_file" ] && conf_append "resolv-file" "$resolve_file"
 
 	# upgrade old configuration
 	if [ "$redirect" = "redirect" ] || [ "$redirect" = "dnsmasq-upstream" ] || [ "$redirect" = "none" ]; then
@@ -357,16 +355,15 @@ load_service()
 		stop_forward_dnsmasq "$port"
 		stop_forward_dnsmasq "$old_port"
 		[ "$redirect" = "none" ] || {
-			uci delete smartdns.@smartdns[0].port="53" 2>/dev/null
+			uci -q delete smartdns.@smartdns[0].port="53"
 			port="53"
 		}
-		uci delete smartdns.@smartdns[0].redirect 2>/dev/null
-		uci delete smartdns.@smartdns[0].old_redirect 2>/dev/null
-		uci delete smartdns.@smartdns[0].old_enabled 2>/dev/null
+		uci -q delete smartdns.@smartdns[0].redirect
+		uci -q delete smartdns.@smartdns[0].old_redirect
+		uci -q delete smartdns.@smartdns[0].old_enabled
 	fi
 
 	SMARTDNS_PORT="$port"
-	[ -z "${dnsmasq_port}" ] && dnsmasq_port="53"
 	[ "$old_port" == "53" ] && [ "$dnsmasq_port" = "0" ] && {
 		[ "$SMARTDNS_PORT" = "53" ] || stop_main_dns
 		[ "$enabled" = "0" ] && stop_main_dns
@@ -376,8 +373,8 @@ load_service()
 		[ "$SMARTDNS_PORT" = "53" ] || stop_set_dnsmasq "$SMARTDNS_PORT" "$old_port"
 	}
 
-	uci delete smartdns.@smartdns[0].old_port 2>/dev/null
-	uci set smartdns.@smartdns[0].old_port="$SMARTDNS_PORT" 2>/dev/null
+	uci -q delete smartdns.@smartdns[0].old_port
+	uci -q set smartdns.@smartdns[0].old_port="$SMARTDNS_PORT"
 	uci commit smartdns
 
 	[ "$enabled" -gt 0 ] || return 1
@@ -407,8 +404,6 @@ load_service()
 
 	config_foreach load_server "server"
 
-	[ "$UPSTREAM_SERVER_NUM" -gt "0" ] || load_resolv_conf
-
 	{
 		echo "conf-file $ADDRESS_CONF"
 		echo "conf-file $BLACKLIST_IP_CONF"
@@ -435,9 +430,10 @@ load_service()
 unload_service()
 {
 	local section="$1"
-	dnsmasq_port="$(uci get dhcp.@dnsmasq[0].port 2>/dev/null)"
+	dnsmasq_port="$(uci -q get dhcp.@dnsmasq[0].port)"
 	config_get port "$section" "port" "53"
 	config_get old_port "$section" "old_port" "0"
+	config_get auto_set_dnsmasq "$section" "auto_set_dnsmasq" "0"
 	[ -z "${dnsmasq_port}" ] && dnsmasq_port="53"
 	[ "$old_port" = "53" ] && [ "$dnsmasq_port" = "0" ] && stop_main_dns
 	[ "$auto_set_dnsmasq" = "1" ] && {
@@ -445,6 +441,12 @@ unload_service()
 	}
 }
 
+service_stopped()
+{
+	config_load "smartdns"
+	config_foreach unload_service "smartdns"
+}
+
 start_service()
 {
 	config_load "smartdns"
@@ -456,9 +458,3 @@ reload_service()
 	stop
 	start
 }
-
-stop_service()
-{
-	config_load "smartdns"
-	config_foreach unload_service "smartdns"
-}
diff --git a/src/dns_conf.c b/src/dns_conf.c
index df5a707..684fc1b 100644
--- a/src/dns_conf.c
+++ b/src/dns_conf.c
@@ -32,6 +32,7 @@
 
 #define DEFAULT_DNS_CACHE_SIZE 512
 #define DNS_MAX_REPLY_IP_NUM 8
+#define DNS_RESOLV_FILE "/etc/resolv.conf"
 
 /* ipset */
 struct dns_ipset_table {
@@ -133,6 +134,7 @@ char dns_conf_user[DNS_CONF_USRNAME_LEN];
 
 int dns_save_fail_packet;
 char dns_save_fail_packet_dir[DNS_MAX_PATH];
+char dns_resolv_file[DNS_MAX_PATH];
 
 /* ECS */
 struct dns_edns_client_subnet dns_conf_ipv4_ecs;
@@ -1926,6 +1928,7 @@ static struct config_item _config_item[] = {
 	CONF_STRING("ca-path", (char *)&dns_conf_ca_path, DNS_MAX_PATH),
 	CONF_STRING("user", (char *)&dns_conf_user, sizeof(dns_conf_user)),
 	CONF_YESNO("debug-save-fail-packet", &dns_save_fail_packet),
+	CONF_STRING("resolv-file", (char *)&dns_resolv_file, sizeof(dns_resolv_file)),
 	CONF_STRING("debug-save-fail-packet-dir", (char *)&dns_save_fail_packet_dir, sizeof(dns_save_fail_packet_dir)),
 	CONF_CUSTOM("conf-file", config_addtional_file, NULL),
 	CONF_END(),
@@ -2106,6 +2109,10 @@ static int _dns_conf_load_post(void)
 		dns_conf_local_ttl = dns_conf_rr_ttl_min;
 	}
 
+	if (dns_resolv_file[0] == '\0') {
+		safe_strncpy(dns_resolv_file, DNS_RESOLV_FILE, sizeof(dns_resolv_file));
+	}
+
 	return 0;
 }
 
diff --git a/src/dns_conf.h b/src/dns_conf.h
index cb9b283..3229cda 100644
--- a/src/dns_conf.h
+++ b/src/dns_conf.h
@@ -325,6 +325,7 @@ extern char dns_conf_sni_proxy_ip[DNS_MAX_IPLEN];
 
 extern int dns_save_fail_packet;
 extern char dns_save_fail_packet_dir[DNS_MAX_PATH];
+extern char dns_resolv_file[DNS_MAX_PATH];
 
 void dns_server_load_exit(void);
 
diff --git a/src/dns_server.c b/src/dns_server.c
index a3c968d..592e39a 100644
--- a/src/dns_server.c
+++ b/src/dns_server.c
@@ -793,7 +793,7 @@ static int _dns_setup_dns_raw_packet(struct dns_server_post_context *context)
 	/* encode to binary data */
 	int encode_len = dns_encode(context->inpacket, context->inpacket_maxlen, context->packet);
 	if (encode_len <= 0) {
-		tlog(TLOG_ERROR, "encode raw packet failed for %s", context->request->domain);
+		tlog(TLOG_DEBUG, "encode raw packet failed for %s", context->request->domain);
 		return -1;
 	}
 
diff --git a/src/smartdns.c b/src/smartdns.c
index 025f42c..9e50fef 100644
--- a/src/smartdns.c
+++ b/src/smartdns.c
@@ -44,7 +44,6 @@
 #include <sys/types.h>
 #include <ucontext.h>
 
-#define RESOLVE_FILE "/etc/resolv.conf"
 #define MAX_LINE_LEN 1024
 #define MAX_KEY_LEN 64
 #define SMARTDNS_PID_FILE "/var/run/smartdns.pid"
@@ -173,9 +172,9 @@ static int _smartdns_load_from_resolv(void)
 	int filed_num = 0;
 	int line_num = 0;
 
-	fp = fopen(RESOLVE_FILE, "r");
+	fp = fopen(dns_resolv_file, "r");
 	if (fp == NULL) {
-		tlog(TLOG_ERROR, "open %s failed, %s", RESOLVE_FILE, strerror(errno));
+		tlog(TLOG_ERROR, "open %s failed, %s", dns_resolv_file, strerror(errno));
 		return -1;
 	}