diff --git a/core/config.go b/core/config.go
index 935f696..87f46b0 100644
--- a/core/config.go
+++ b/core/config.go
@@ -42,14 +42,13 @@ type AppConfig struct {
 	connectTime      time.Time
 	fromToken        uint64
 	linkMode         string
-	isUnderlayServer int // TODO: bool?
+	isUnderlayServer int
 }
 
 func (c *AppConfig) ID() string {
 	return fmt.Sprintf("%s%d", c.Protocol, c.SrcPort)
 }
 
-// TODO: add loglevel, maxlogfilesize
 type Config struct {
 	Network    NetworkConfig `json:"network"`
 	Apps       []*AppConfig  `json:"apps"`
@@ -150,7 +149,7 @@ func (c *Config) load() error {
 	return err
 }
 
-// TODO: deal with multi-thread r/w
+// deal with multi-thread r/w
 func (c *Config) setToken(token uint64) {
 	c.mtx.Lock()
 	defer c.mtx.Unlock()
diff --git a/core/nat.go b/core/nat.go
index 223be38..1fd9a08 100644
--- a/core/nat.go
+++ b/core/nat.go
@@ -97,7 +97,6 @@ func getNATType(host string, udp1 int, udp2 int) (publicIP string, NATType int,
 		return "", 0, 0, 0, err
 	}
 	hasIPv4, hasUPNPorNATPMP := publicIPTest(ip1, echoPort)
-	gLog.Printf(LvINFO, "local port:%d, nat port:%d, hasIPv4:%d, UPNP:%d", localPort, port1, hasIPv4, hasUPNPorNATPMP)
 	_, port2, err := natTest(host, udp2, localPort) // 2rd nat test not need testing publicip
 	gLog.Printf(LvDEBUG, "local port:%d  nat port:%d", localPort, port2)
 	if err != nil {
diff --git a/core/openp2p.go b/core/openp2p.go
index 0c414e8..a6b2a5d 100644
--- a/core/openp2p.go
+++ b/core/openp2p.go
@@ -14,7 +14,6 @@ func Run() {
 	baseDir := filepath.Dir(os.Args[0])
 	os.Chdir(baseDir) // for system service
 	gLog = NewLogger(baseDir, ProductName, LvDEBUG, 1024*1024, LogFile|LogConsole)
-	// TODO: install sub command, deamon process
 	if len(os.Args) > 1 {
 		switch os.Args[1] {
 		case "version", "-v", "--version":
@@ -51,7 +50,7 @@ func Run() {
 		gLog.Println(LvERROR, "P2PNetwork login error")
 		return
 	}
-	gLog.Println(LvINFO, "waiting for connection...")
+	// gLog.Println(LvINFO, "waiting for connection...")
 	forever := make(chan bool)
 	<-forever
 }
@@ -82,7 +81,7 @@ func RunAsModule(baseDir string, token string, bw int, logLevel int) *P2PNetwork
 		gLog.Println(LvERROR, "P2PNetwork login error")
 		return nil
 	}
-	gLog.Println(LvINFO, "waiting for connection...")
+	// gLog.Println(LvINFO, "waiting for connection...")
 	return network
 }
 
diff --git a/core/update.go b/core/update.go
index 95a271e..ab5829c 100644
--- a/core/update.go
+++ b/core/update.go
@@ -70,7 +70,6 @@ func update(host string, port int) error {
 	return nil
 }
 
-// todo rollback on error
 func updateFile(url string, checksum string, dst string) error {
 	gLog.Println(LvINFO, "download ", url)
 	tmpFile := filepath.Dir(os.Args[0]) + "/openp2p.tmp"
@@ -110,11 +109,12 @@ func updateFile(url string, checksum string, dst string) error {
 	output.Close()
 	gLog.Println(LvINFO, "download ", url, " ok")
 	gLog.Printf(LvINFO, "size: %d bytes", n)
-
-	err = os.Rename(os.Args[0], os.Args[0]+"0") // the old daemon process was using the 0 file, so it will prevent override it
+	backupFile := os.Args[0] + "0"
+	err = os.Rename(os.Args[0], backupFile) // the old daemon process was using the 0 file, so it will prevent override it
 	if err != nil {
 		gLog.Printf(LvINFO, " rename %s error:%s, retry 1", os.Args[0], err)
-		err = os.Rename(os.Args[0], os.Args[0]+"1")
+		backupFile = os.Args[0] + "1"
+		err = os.Rename(os.Args[0], backupFile)
 		if err != nil {
 			gLog.Printf(LvINFO, " rename %s error:%s", os.Args[0], err)
 		}
@@ -124,7 +124,7 @@ func updateFile(url string, checksum string, dst string) error {
 	err = extract(filepath.Dir(os.Args[0]), tmpFile)
 	if err != nil {
 		gLog.Printf(LvERROR, "extract error:%s. revert rename", err)
-		os.Rename(os.Args[0]+"0", os.Args[0])
+		os.Rename(backupFile, os.Args[0])
 		return err
 	}
 	os.Remove(tmpFile)
@@ -218,12 +218,16 @@ func extractTgz(dst, src string) error {
 }
 
 func cleanTempFiles() {
-	err := os.Remove(os.Args[0] + "0")
-	if err != nil {
-		gLog.Printf(LvDEBUG, " remove %s error:%s", os.Args[0]+"0", err)
+	tmpFile := os.Args[0] + "0"
+	if _, err := os.Stat(tmpFile); err == nil {
+		if err := os.Remove(tmpFile); err != nil {
+			gLog.Printf(LvDEBUG, " remove %s error:%s", tmpFile, err)
+		}
 	}
-	err = os.Remove(os.Args[0] + "1")
-	if err != nil {
-		gLog.Printf(LvDEBUG, " remove %s error:%s", os.Args[0]+"0", err)
+	tmpFile = os.Args[0] + "1"
+	if _, err := os.Stat(tmpFile); err == nil {
+		if err := os.Remove(tmpFile); err != nil {
+			gLog.Printf(LvDEBUG, " remove %s error:%s", tmpFile, err)
+		}
 	}
 }
diff --git a/core/upnp.go b/core/upnp.go
index 7a7e633..c4672cc 100644
--- a/core/upnp.go
+++ b/core/upnp.go
@@ -358,11 +358,6 @@ func (n *upnpNAT) AddPortMapping(protocol string, externalPort, internalPort int
 		return
 	}
 
-	// TODO: check response to see if the port was forwarded
-	// log.Println(message, response)
-	// JAE:
-	// body, err := ioutil.ReadAll(response.Body)
-	// fmt.Println(string(body), err)
 	mappedExternalPort = externalPort
 	_ = response
 	return
@@ -384,8 +379,6 @@ func (n *upnpNAT) DeletePortMapping(protocol string, externalPort, internalPort
 		return
 	}
 
-	// TODO: check response to see if the port was deleted
-	// log.Println(message, response)
 	_ = response
 	return
 }