Chapter 6 Mac Address Table Configuration - Zte ZXR10 5900E Series Configuration Manual

Creating and Deleting a MAC Address Table
In the initial status, a switch does not have a MAC address table. To realize fast forwarding,
you must create a MAC address table for the switch. The capacity of the MAC address
table is limited, and the network devices change frequently, so you must delete old entries
from the MAC address table and update the changed ones.
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Dynamic Learning
The dynamic MAC addresses in the MAC address table are learned dynamically by a
switch. The learning process is as follows:
When a port of the switch receives a data frame, the switch analyzes the source MAC
address and VLAN ID (assume that they are MAC1 + VID1) in the frame. If the MAC
address is legal and can be learned, the switch uses MAC1 + VID1 as the key to query
the MAC address table. If MAC1 + VID1 cannot be found in the MAC address table,
the switch adds it to the table. If MAC1 + VID1 can be found in the table, the switch
updates the corresponding entry in the table.
Note:
MAC address learning is to learn the source MAC address in the data frame,
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instead of the destination MAC address.
For MAC address learning, only unicast addresses can be learned. Broadcast or
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multicast addresses cannot be learned.
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MAC Address Aging
The capacity of the MAC address table is limited. To effectively use the resources in
the MAC address table, the switch provides MAC address aging.
If the switch does not receive any data frame from a device during the specified period
(the aging time), the switch assumes that the device has already left the network. In
this case, the switch deletes the corresponding MAC address from the MAC address
table. In this way, the MAC address table can be updated in time. MAC address aging
is applied only to dynamic MAC addresses.
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Adding or Deleting a MAC Address Manually
If the network is comparatively stable and the switch port connecting a device is fixed,
you can use the configuration commands to add the MAC address directly in the
MAC address table of the switch. The MAC address can be configured as a static
or permanent one. Adding static or permanent MAC addresses can prevent network
attacks that use fraudulent MAC addresses.
The added MAC addresses can be deleted by using the command of deleting a MAC
address. This command can also be used to delete a dynamic MAC address forcedly
and make the switch learn the address again.
SJ-20150114102049-002|2015-01-15 (R1.0)

Chapter 6 MAC Address Table Configuration

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