diff --git a/cmd/frpc/sub/root.go b/cmd/frpc/sub/root.go
index 7f09c03e..9b9a2262 100644
--- a/cmd/frpc/sub/root.go
+++ b/cmd/frpc/sub/root.go
@@ -69,6 +69,7 @@ var (
 	sk                string
 	serverName        string
 	bindAddr          string
+	bindPort          int
 )
 
 func init() {
diff --git a/cmd/frpc/sub/stcp.go b/cmd/frpc/sub/stcp.go
index d3a5d4af..4915e520 100644
--- a/cmd/frpc/sub/stcp.go
+++ b/cmd/frpc/sub/stcp.go
@@ -39,7 +39,8 @@ func init() {
 	stcpCmd.PersistentFlags().StringVarP(&serverName, "server_name", "", "", "server name")
 	stcpCmd.PersistentFlags().StringVarP(&localIp, "local_ip", "i", "127.0.0.1", "local ip")
 	stcpCmd.PersistentFlags().IntVarP(&localPort, "local_port", "l", 0, "local port")
-	stcpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr such as 127.0.0.1:9000")
+	stcpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr")
+	stcpCmd.PersistentFlags().IntVarP(&bindPort, "bind_port", "", 0, "bind port")
 	stcpCmd.PersistentFlags().BoolVarP(&useEncryption, "ue", "", false, "use encryption")
 	stcpCmd.PersistentFlags().BoolVarP(&useCompression, "uc", "", false, "use compression")
 
@@ -69,6 +70,7 @@ var stcpCmd = &cobra.Command{
 		cfg.LocalIp = localIp
 		cfg.LocalPort = localPort
 		cfg.BindAddr = bindAddr
+		cfg.BindPort = bindPort
 		cfg.UseEncryption = useEncryption
 		cfg.UseCompression = useCompression
 
diff --git a/cmd/frpc/sub/xtcp.go b/cmd/frpc/sub/xtcp.go
index e7d07526..8c18a859 100644
--- a/cmd/frpc/sub/xtcp.go
+++ b/cmd/frpc/sub/xtcp.go
@@ -39,7 +39,8 @@ func init() {
 	xtcpCmd.PersistentFlags().StringVarP(&serverName, "server_name", "", "", "server name")
 	xtcpCmd.PersistentFlags().StringVarP(&localIp, "local_ip", "i", "127.0.0.1", "local ip")
 	xtcpCmd.PersistentFlags().IntVarP(&localPort, "local_port", "l", 0, "local port")
-	xtcpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr such as 127.0.0.1:9000")
+	xtcpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr")
+	xtcpCmd.PersistentFlags().IntVarP(&bindPort, "bind_port", "", 0, "bind port")
 	xtcpCmd.PersistentFlags().BoolVarP(&useEncryption, "ue", "", false, "use encryption")
 	xtcpCmd.PersistentFlags().BoolVarP(&useCompression, "uc", "", false, "use compression")
 
@@ -69,6 +70,7 @@ var xtcpCmd = &cobra.Command{
 		cfg.LocalIp = localIp
 		cfg.LocalPort = localPort
 		cfg.BindAddr = bindAddr
+		cfg.BindPort = bindPort
 		cfg.UseEncryption = useEncryption
 		cfg.UseCompression = useCompression
 
diff --git a/models/config/proxy.go b/models/config/proxy.go
index 9558f5b0..8b6c0821 100644
--- a/models/config/proxy.go
+++ b/models/config/proxy.go
@@ -675,6 +675,10 @@ func (cfg *StcpProxyConf) CheckForCli() (err error) {
 			err = fmt.Errorf("bind_addr shouldn't be empty")
 			return
 		}
+		if cfg.BindPort == 0 {
+			err = fmt.Errorf("bind_port should be set")
+			return
+		}
 	}
 	return
 }
@@ -777,6 +781,10 @@ func (cfg *XtcpProxyConf) CheckForCli() (err error) {
 			err = fmt.Errorf("bind_addr shouldn't be empty")
 			return
 		}
+		if cfg.BindPort == 0 {
+			err = fmt.Errorf("bind_port should be set")
+			return
+		}
 	}
 	return
 }
diff --git a/server/nathole.go b/server/nathole.go
index 042ffcce..0ad0c48f 100644
--- a/server/nathole.go
+++ b/server/nathole.go
@@ -106,10 +106,17 @@ func (nc *NatHoleController) HandleVisitor(m *msg.NatHoleVisitor, raddr *net.UDP
 	}
 	nc.mu.Lock()
 	clientCfg, ok := nc.clientCfgs[m.ProxyName]
-	if !ok || m.SignKey != util.GetAuthKey(clientCfg.Sk, m.Timestamp) {
+	if !ok {
 		nc.mu.Unlock()
+		log.Debug("xtcp server for [%s] doesn't exist", m.ProxyName)
 		return
 	}
+	if m.SignKey != util.GetAuthKey(clientCfg.Sk, m.Timestamp) {
+		nc.mu.Unlock()
+		log.Debug("xtcp connection of [%s] auth failed", m.ProxyName)
+		return
+	}
+
 	nc.sessions[sid] = session
 	nc.mu.Unlock()
 	log.Trace("handle visitor message, sid [%s]", sid)