diff --git a/mikrotik_ b/mikrotik_
index 3563b50..0a00219 100755
--- a/mikrotik_
+++ b/mikrotik_
@@ -6,22 +6,23 @@ def config(name, port_max, ports_label):
     print(f"graph_title Network flow for {name}")
     print("graph_order down up")
     print("graph_args --base 1000")
-    print("graph_vlabel bits in (-) / out (+) per ${graph_period}")
+    print("graph_vlabel in (-) / out (+)")
     for port in range(1, port_max + 1):
         print(f"down{port}.label {ports_label[port - 1]}")
         print(f"down{port}.type DERIVE")
         print(f"down{port}.graph no")
-        print(f"down{port}.cdef down,8,*")
+        print(f"down{port}.cdef down{port},8,*")
     for port in range(1, port_max + 1):
         print(f"up{port}.label {ports_label[port - 1]}")
         print(f"up{port}.type DERIVE")
-        print(f"up{port}.negative down")
-        print(f"up{port}.cdef up,8,*")
+        print(f"up{port}.negative down{port}")
+        print(f"up{port}.cdef up{port},8,*")
 
 
 if __name__ == '__main__':
     from sys import argv
     import subprocess
+    import re
     ports_label = []
     InOctets = []
     OutOctets = []
@@ -32,8 +33,11 @@ if __name__ == '__main__':
     for line in result.splitlines():
         if "sysName" in line:
             name = line.split()[-1]
+            name = re.sub(r"(^[^A-Za-z_]|[^A-Za-z0-9_])", "_", name)
         if "ifDescr" in line:
-            ports_label.append(line.split()[-1])
+            label = (line.split()[-1])
+            label = re.sub(r"(^[^A-Za-z_]|[^A-Za-z0-9_])", "_", label)
+            ports_label.append(label)
         if "ifIndex" in line:
             port_max += 1
         if "ifInOctets" in line: