diff --git a/example_config/super_mode/n1_test_fd_mode.py b/example_config/super_mode/n1_test_fd_mode.py
index 440eabd..2555640 100644
--- a/example_config/super_mode/n1_test_fd_mode.py
+++ b/example_config/super_mode/n1_test_fd_mode.py
@@ -19,22 +19,19 @@ def signal_handler(sig, frame):
 
 def read_loop(fd):
     print("Main Start read fd:",fd)
-    with os.fdopen(fd, 'rb') as fdfile:
-        while True:
-            text = fdfile.read()
-            if len(text) == 0:
-                print("EOF!!!!!!!!!!!!!!!!!!!!!!!!")
-                break
-            print("Main: RECEIVED:",text)
+    while True:
+        text = os.read(fd, 65535)
+        if len(text) == 0:
+            print("EOF!!!!!!!!!!!!!!!!!!!!!!!!")
+            break
+        print("Main: RECEIVED:",text)
         
 def write_loop(fd):
-    with os.fdopen(fd, 'wb') as fdfile:
-        while True:
-            print("Main Write fd:",fd)
-            text = b'\xff\xff\xff\xff\xff\xff\xaa\xaa\xaa\xaa\xaa\xaa' + b'm'*88
-            fdfile.write(text)
-            fdfile.flush()
-            time.sleep(1)
+    while True:
+        print("Main Write fd:",fd)
+        text = b'\xff\xff\xff\xff\xff\xff\xaa\xaa\xaa\xaa\xaa\xaa' + b'm'*88
+        os.write(fd,text)
+        time.sleep(1)
             
 tr = threading.Thread(target = read_loop,  args=(pr,))
 tr.start()
@@ -48,8 +45,8 @@ os.environ["EG_FD_TX"] = str(ew)
 print(str(er), str(ew))
 
 #p = subprocess.Popen('./etherguard-go -config example_config/super_mode/n1_fd.yaml -mode edge'.split(" "),pass_fds=[er,ew])
-#p = subprocess.Popen('python3 example_config/super_mode/n1_test_fd_mode2.py'.split(" "),pass_fds=[er,ew])
-p = subprocess.Popen('example_config/super_mode/n1_test_fd_mode2'.split(" "),pass_fds=[er,ew])
+p = subprocess.Popen('python3 example_config/super_mode/n1_test_fd_mode2.py'.split(" "),pass_fds=[er,ew])
+#p = subprocess.Popen('example_config/super_mode/n1_test_fd_mode2'.split(" "),pass_fds=[er,ew])
 
 os.close(er)
 os.close(ew)
diff --git a/example_config/super_mode/n1_test_fd_mode2.py b/example_config/super_mode/n1_test_fd_mode2.py
index 69ea5bd..b214d13 100644
--- a/example_config/super_mode/n1_test_fd_mode2.py
+++ b/example_config/super_mode/n1_test_fd_mode2.py
@@ -19,22 +19,19 @@ def signal_handler(sig, frame):
     
 def read_loop(fd):
     print("Sub: Start read fd:",fd)
-    with os.fdopen(fd, 'rb') as fdfile:
-        while True:
-            text = fdfile.read()
-            if len(text) == 0:
-                print("EOF!!!!!!!!!!!!!!!!!!!!!!!!")
-                break
-            print("Sub RECEIVED:",text)
+    while True:
+        text = os.read(fd, 65535)
+        if len(text) == 0:
+            print("EOF!!!!!!!!!!!!!!!!!!!!!!!!")
+            break
+        print("Sub RECEIVED:",text)
         
 def write_loop(fd):
-    with os.fdopen(fd, 'wb') as fdfile:
-        while True:
-            print("Sub: Write fd:",fd)
-            text = b'\xff\xff\xff\xff\xff\xff\xaa\xaa\xaa\xaa\xaa\xaa' + b's'*88
-            fdfile.write(text)
-            fdfile.flush()
-            time.sleep(1)
+    while True:
+        print("Sub: Write fd:",fd)
+        text = b'\xff\xff\xff\xff\xff\xff\xaa\xaa\xaa\xaa\xaa\xaa' + b's'*88
+        os.write(fd,text)
+        time.sleep(1)
             
 tr = threading.Thread(target = read_loop,  args=(er,))
 tr.start()
diff --git a/tap/tap_sock.go b/tap/tap_sock.go
index d0c34ab..99b0bc1 100644
--- a/tap/tap_sock.go
+++ b/tap/tap_sock.go
@@ -53,6 +53,9 @@ func CreateSockTAP(iconfig config.InterfaceConf, protocol string, NodeID config.
 	if iconfig.SendAddr != "" {
 		client, err := net.Dial(protocol, iconfig.SendAddr)
 		if err != nil {
+			if tap.server != nil {
+				(*tap.server).Close()
+			}
 			return nil, err
 		}
 		tap.connTx = &client