diff --git a/cmd/netstack/main.go b/cmd/netstack/main.go
index 4d87cd8..2b68c47 100644
--- a/cmd/netstack/main.go
+++ b/cmd/netstack/main.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"net"
+	"netstack/logger"
 	"netstack/tcpip"
 	"netstack/tcpip/link/fdbased"
 	"netstack/tcpip/link/tuntap"
@@ -140,6 +141,7 @@ func main() {
 	//	conn.Close()
 	//}()
 
+	//logger.SetFlags(logger.TCP)
 	go func() { // echo server
 		listener := tcpListen(s, proto, addr, localPort)
 		conn, err := listener.Accept()
@@ -150,7 +152,9 @@ func main() {
 		if _, err := conn.Read(buf); err != nil {
 			log.Fatal(err)
 		}
-		fmt.Println(string(buf))
+		logger.GetInstance().Info(logger.TCP, func() {
+			fmt.Println(string(buf))
+		})
 		if string(buf) != "" {
 			conn.Write([]byte("Server echo"))
 		}
diff --git a/logger/logger.go b/logger/logger.go
new file mode 100644
index 0000000..6f21179
--- /dev/null
+++ b/logger/logger.go
@@ -0,0 +1,49 @@
+package logger
+
+import (
+	"sync"
+)
+
+const (
+	IP = 1 << iota
+	UDP
+	TCP
+)
+
+type logger struct {
+	flags uint8
+}
+
+var instance *logger
+var once sync.Once
+
+// GetInstance 获取日志实例
+func GetInstance() *logger {
+	once.Do(func() {
+		instance = &logger{
+			//flags: 255,
+		}
+	})
+	return instance
+}
+
+// SetFlags 设置输出类型
+func SetFlags(flags uint8) {
+	GetInstance().flags = flags
+}
+
+/*
+logger.GetInstance(IP|TCP)
+
+logger.GetInstance().Info(logger.IP, msg) // 会输出
+
+logger.GetInstance().Info(logger.UDP, msg) // 不会输出
+
+
+*/
+
+func (l *logger) Info(mask uint8, f func()) {
+	if mask&l.flags != 0 {
+		f()
+	}
+}
diff --git a/tcpip/network/ipv4/ipv4.go b/tcpip/network/ipv4/ipv4.go
index 5b0d8e6..aff1149 100644
--- a/tcpip/network/ipv4/ipv4.go
+++ b/tcpip/network/ipv4/ipv4.go
@@ -2,6 +2,7 @@ package ipv4
 
 import (
 	"log"
+	"netstack/logger"
 	"netstack/tcpip"
 	"netstack/tcpip/buffer"
 	"netstack/tcpip/header"
@@ -129,7 +130,9 @@ func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) {
 	if !h.IsValid(vv.Size()) {
 		return
 	}
-	log.Println(h)
+	logger.GetInstance().Info(logger.IP, func() {
+		log.Println(h)
+	})
 
 	hlen := int(h.HeaderLength())
 	tlen := int(h.TotalLength())
diff --git a/tcpip/transport/tcp/segment.go b/tcpip/transport/tcp/segment.go
index eab7a3b..d938b48 100644
--- a/tcpip/transport/tcp/segment.go
+++ b/tcpip/transport/tcp/segment.go
@@ -3,6 +3,7 @@ package tcp
 import (
 	"fmt"
 	"log"
+	"netstack/logger"
 	"netstack/tcpip/buffer"
 	"netstack/tcpip/header"
 	"netstack/tcpip/seqnum"
@@ -122,8 +123,10 @@ func (s *segment) parse() bool {
 	s.options = h.Options()
 	s.parsedOptions = header.ParseTCPOptions(s.options)
 
-	log.Println(h)
-	fmt.Println(s.parsedOptions)
+	logger.GetInstance().Info(logger.TCP, func() {
+		log.Println(h)
+		fmt.Println(s.parsedOptions)
+	})
 
 	s.data.TrimFront(offset)