diff --git a/cmd/cmd.go b/cmd/cmd.go
index b50c570..3faf70e 100644
--- a/cmd/cmd.go
+++ b/cmd/cmd.go
@@ -35,7 +35,7 @@ func Excute() {
 	tcp := parser.Flag("T", "tcp", &argparse.Options{Help: "Use TCP SYN for tracerouting (default port is 80)"})
 	udp := parser.Flag("U", "udp", &argparse.Options{Help: "Use UDP SYN for tracerouting (default port is 33494)"})
 	fast_trace := parser.Flag("F", "fast-trace", &argparse.Options{Help: "One-Key Fast Trace to China ISPs"})
-	port := parser.Int("p", "port", &argparse.Options{Help: "Set the destination port to use. With default of 80 for \"tcp\", 33494 for \"udp\""})
+	port := parser.Int("p", "port", &argparse.Options{Help: "Set the destination port to use. With default of 80 for \"tcp\", 33494 for \"udp\"", Default: 80})
 	numMeasurements := parser.Int("q", "queries", &argparse.Options{Default: 3, Help: "Set the number of probes per each hop"})
 	parallelRequests := parser.Int("", "parallel-requests", &argparse.Options{Default: 18, Help: "Set ParallelRequests number. It should be 1 when there is a multi-routing"})
 	maxHops := parser.Int("m", "max-hops", &argparse.Options{Default: 30, Help: "Set the max number of hops (max TTL to be reached)"})
@@ -96,16 +96,28 @@ func Excute() {
 		os.Exit(0)
 	}
 
+	if !*tcp && *port == 80 {
+		*port = 33494
+	}
+
 	domain := *str
 
-	if *port == 0 {
-		*port = 80
+	var m trace.Method
+
+	switch {
+	case *tcp:
+		m = trace.TCPTrace
+	case *udp:
+		m = trace.UDPTrace
+	default:
+		m = trace.ICMPTrace
 	}
 
 	if *fast_trace || *file != "" {
 		var paramsFastTrace = fastTrace.ParamsFastTrace{
 			SrcDev:         *srcDev,
 			SrcAddr:        *srcAddr,
+			DestPort:       *port,
 			BeginHop:       *beginHop,
 			MaxHops:        *maxHops,
 			RDns:           !*noRdns,
@@ -118,7 +130,7 @@ func Excute() {
 			Dot:            *dot,
 		}
 
-		fastTrace.FastTest(*tcp, *output, paramsFastTrace)
+		fastTrace.FastTest(m, *output, paramsFastTrace)
 		if *output {
 			fmt.Println("您的追踪日志已经存放在 /tmp/trace.log 中")
 		}
@@ -240,25 +252,10 @@ func Excute() {
 		}
 	}
 
-	var m trace.Method
-
-	switch {
-	case *tcp:
-		m = trace.TCPTrace
-	case *udp:
-		m = trace.UDPTrace
-	default:
-		m = trace.ICMPTrace
-	}
-
 	if !*jsonPrint {
 		printer.PrintTraceRouteNav(ip, domain, *dataOrigin, *maxHops, *packetSize, *srcAddr, string(m))
 	}
 
-	if !*tcp && *port == 80 {
-		*port = 33494
-	}
-
 	util.DestIP = ip.String()
 	var conf = trace.Config{
 		DN42:             *dn42,
diff --git a/fast_trace/fast_trace ipv6.go b/fast_trace/fast_trace ipv6.go
index 97dc60a..6d31473 100644
--- a/fast_trace/fast_trace ipv6.go	
+++ b/fast_trace/fast_trace ipv6.go	
@@ -29,7 +29,7 @@ func (f *FastTracer) tracert_v6(location string, ispCollection ISPCollection) {
 	var conf = trace.Config{
 		BeginHop:         f.ParamsFastTrace.BeginHop,
 		DestIP:           ip,
-		DestPort:         80,
+		DestPort:         f.ParamsFastTrace.DestPort,
 		MaxHops:          f.ParamsFastTrace.MaxHops,
 		NumMeasurements:  3,
 		ParallelRequests: 18,
@@ -124,7 +124,7 @@ func (f *FastTracer) testFast_v6() {
 	//f.tracert_v6(TestIPsCollection.Beijing.Location, TestIPsCollection.Beijing.CST)
 }
 
-func FastTestv6(tm bool, outEnable bool, paramsFastTrace ParamsFastTrace) {
+func FastTestv6(traceMode trace.Method, outEnable bool, paramsFastTrace ParamsFastTrace) {
 	var c string
 
 	oe = outEnable
@@ -148,11 +148,14 @@ func FastTestv6(tm bool, outEnable bool, paramsFastTrace ParamsFastTrace) {
 		w.Conn.Close()
 	}()
 
-	if !tm {
+	switch traceMode {
+	case trace.ICMPTrace:
 		ft.TracerouteMethod = trace.ICMPTrace
-		fmt.Println("您将默认使用ICMP协议进行路由跟踪，如果您想使用TCP SYN进行路由跟踪，可以加入 -T 参数")
-	} else {
+	case trace.TCPTrace:
 		ft.TracerouteMethod = trace.TCPTrace
+	case trace.UDPTrace:
+		fmt.Println("[Info] IPv6 UDP Traceroute is not supported right now.")
+		os.Exit(0)
 	}
 
 	switch c {
diff --git a/fast_trace/fast_trace.go b/fast_trace/fast_trace.go
index 6c90e98..3e9f134 100644
--- a/fast_trace/fast_trace.go
+++ b/fast_trace/fast_trace.go
@@ -26,6 +26,7 @@ type FastTracer struct {
 type ParamsFastTrace struct {
 	SrcDev         string
 	SrcAddr        string
+	DestPort       int
 	BeginHop       int
 	MaxHops        int
 	RDns           bool
@@ -58,7 +59,7 @@ func (f *FastTracer) tracert(location string, ispCollection ISPCollection) {
 	var conf = trace.Config{
 		BeginHop:         f.ParamsFastTrace.BeginHop,
 		DestIP:           ip,
-		DestPort:         80,
+		DestPort:         f.ParamsFastTrace.DestPort,
 		MaxHops:          f.ParamsFastTrace.MaxHops,
 		NumMeasurements:  3,
 		ParallelRequests: 18,
@@ -103,13 +104,13 @@ func (f *FastTracer) tracert(location string, ispCollection ISPCollection) {
 	fmt.Println()
 }
 
-func FastTest(tm bool, outEnable bool, paramsFastTrace ParamsFastTrace) {
+func FastTest(traceMode trace.Method, outEnable bool, paramsFastTrace ParamsFastTrace) {
 	// tm means tcp mode
 	var c string
 	oe = outEnable
 
 	if paramsFastTrace.File != "" {
-		testFile(paramsFastTrace, tm)
+		testFile(paramsFastTrace, traceMode)
 		return
 	}
 
@@ -139,7 +140,7 @@ func FastTest(tm bool, outEnable bool, paramsFastTrace ParamsFastTrace) {
 				}
 			}
 		}
-		FastTestv6(tm, outEnable, paramsFastTrace)
+		FastTestv6(traceMode, outEnable, paramsFastTrace)
 		return
 	}
 	if paramsFastTrace.SrcDev != "" {
@@ -180,11 +181,13 @@ func FastTest(tm bool, outEnable bool, paramsFastTrace ParamsFastTrace) {
 		w.Conn.Close()
 	}()
 
-	if !tm {
+	switch traceMode {
+	case trace.ICMPTrace:
 		ft.TracerouteMethod = trace.ICMPTrace
-		fmt.Println("您将默认使用ICMP协议进行路由跟踪，如果您想使用TCP SYN进行路由跟踪，可以加入 -T 参数")
-	} else {
+	case trace.TCPTrace:
 		ft.TracerouteMethod = trace.TCPTrace
+	case trace.UDPTrace:
+		ft.TracerouteMethod = trace.UDPTrace
 	}
 
 	switch c {
@@ -205,7 +208,7 @@ func FastTest(tm bool, outEnable bool, paramsFastTrace ParamsFastTrace) {
 	}
 }
 
-func testFile(paramsFastTrace ParamsFastTrace, tm bool) {
+func testFile(paramsFastTrace ParamsFastTrace, traceMode trace.Method) {
 	// 建立 WebSocket 连接
 	w := wshandle.New()
 	w.Interrupt = make(chan os.Signal, 1)
@@ -215,11 +218,13 @@ func testFile(paramsFastTrace ParamsFastTrace, tm bool) {
 	}()
 
 	var tracerouteMethod trace.Method
-	if !tm {
+	switch traceMode {
+	case trace.ICMPTrace:
 		tracerouteMethod = trace.ICMPTrace
-		fmt.Println("您将默认使用ICMP协议进行路由跟踪，如果您想使用TCP SYN进行路由跟踪，可以加入 -T 参数")
-	} else {
+	case trace.TCPTrace:
 		tracerouteMethod = trace.TCPTrace
+	case trace.UDPTrace:
+		tracerouteMethod = trace.UDPTrace
 	}
 
 	filePath := paramsFastTrace.File
@@ -331,7 +336,7 @@ func testFile(paramsFastTrace ParamsFastTrace, tm bool) {
 		var conf = trace.Config{
 			BeginHop:         paramsFastTrace.BeginHop,
 			DestIP:           net.ParseIP(ip.Ip),
-			DestPort:         80,
+			DestPort:         paramsFastTrace.DestPort,
 			MaxHops:          paramsFastTrace.MaxHops,
 			NumMeasurements:  3,
 			ParallelRequests: 18,