Aging Time Of Mac Address Entries; Limitations On The Number Of Mac Addresses Learnt - Huawei Quidway S3100 Series Operation Manual

MAC
Operation Manual –
Quidway S3100 Series Ethernet Switches
Note:
Among the two types of packets (unicast packets and broadcast packets), the MAC
address learning mechanism enables a switch to learn MAC addresses from only
unicast packets.

1.1.4 Aging Time of MAC Address Entries

As mentioned previously, an Ethernet switch can acquire MAC addresses of network
devices from its ports and add MAC address entries accordingly in its MAC address
table.
The MAC address table is updated regularly. That is, the switch updates the aging time
of an existing MAC address entry if it learns the same MAC address again before the
specified aging time expires, and removes an existing MAC address entry if it does not
learn the same MAC address again when the specified aging time expires.
Note the following when setting the aging time:
If the aging time is too long, the number of the invalid MAC address entries
maintained by the switch may be too many to make room for the MAC address
table. In this case, the MAC address table cannot vary with network changes in
time.
If the aging time is too short, MAC address entries that are still valid may be
removed. This results in large amount of broadcast packets wandering across the
network and decreases the performance of the switches.
Note:
Aging time only applies to dynamic MAC address entries.

1.1.5 Limitations on the Number of MAC Addresses Learnt

The MAC address learning mechanism enables an Ethernet switch to acquire the MAC
addresses of the network devices on the segment connected to the ports of the switch.
By setting the maximum numbers of MAC addresses that can be learnt from individual
ports, you can control the number of the MAC address entries the MAC address table
can dynamically maintains. When the number of the MAC address entries learnt from a
port reaches the set value, the port stops learning MAC addresses.
Forwarding Table
Address
Huawei Technologies Proprietary
Chapter 1 MAC Address Table Management
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