Limiting the Number of MAC Addresses Learned from Each Logical Interface
You can configure a limit to the number of MAC addresses learned from the logical interfaces on an MX Series router.
To configure a limit to the total number of MAC addresses that can be learned from the logical interfaces, include the global-mac-limit limit statement at the [edit protocols l2-learning] hierarchy level:
The default limit to the number of MAC addresses that can be learned the router as a whole is 393,215. The range that you can configure for the router as a whole is 20 through 1,048,575.
After the configured MAC address limit is reached, the default is for packets to be forwarded. You can specify that the packets be dropped by including the packet-action drop statement at the [edit protocols l2-learning global-mac-limit] hierarchy level:
You can also configure a limit to the number of MAC address learned from all the interfaces in a bridge domain or from a specific logical interface only. For more information, see Layer 2 Learning and Forwarding for Bridge Domains Overview.
 | Note: On MX Series routers running Junos OS Release 8.4 and later, statistics for an aged destination MAC entry are not retained. In addition, source and destination statistics are reset during a MAC move. In previous releases, only source statistics were reset during a MAC move. |
