Manual
+7(495) 797-3311 www.qtech.ru 
Москва, Новозаводская ул., 18, стр. 1 
166 
   Spanning  Tree  is  enabled  and  the  port  is  in  “discarding”  status; or the device is just 
connected to  the port and  Spanning Tree is still  under calculation,  wait until the 
Spanning Tree calculation finishes, and the port will learn the MAC address. 
   If  not  the  problems  mentioned  above,  please  check  for  the  switch  portand  contact 
technical support for solution. 
19.5 MAC Address Function Extension 
19.5.1 MAC Address Binding 
19.5.1.1 Introduction to MAC Address Binding 
Most switches support MAC address learning, each port can dynamically learn several MAC 
addresses, so that forwarding data streams between known MAC addresses within the ports 
can be achieved.  If a MAC  address is  aged, the packet  destined for that entry  will be 
broadcasted. In other words, a MAC address learned in a port will be used for forwarding in 
that port, if the connection is changed to another port, the switch will learn the MAC address 
again to forward data in the new port. 
However, in some cases, security or management policy may require MAC addresses to be 
bound with the ports, only data stream from the binding MAC are allowed to be forwarded in 
the ports. That is to say, after a MAC address is bound to a port, only the data stream destined 
for that  MAC address can  flow in from the  binding port,  data stream  destined  for the other 
MAC addresses that not bound to the port will not be allowed to pass through the port. 
19.5.1.2 MAC Address Binding Configuration Task List 
1.  Enable MAC address binding function for the ports 
2.  Lock the MAC addresses for a port 
3.  MAC address binding property configuration 
1.  Enable MAC address binding function for the ports 
Command 
Explanation 
Port Mode 
switchport port-security 
no switchport port-security 
Enable MAC address binding function for the 
port and lock the port. When a port is locked, 
the  MAC  address  learning  function  for  the 
port will be disabled:  the  “no  switchport  port-
security” command disables the MAC address 
binding function for the port, and restores the 
MAC address learning function for the port. 










