1-4
Aging timer only takes effect on dynamic MAC address entries.
Entries in a MAC address table
Entries in a MAC address table fall into the following categories according to their characteristics and
configuration methods:
z Static MAC address entry: Also known as permanent MAC address entry. This type of MAC
address entries are added/removed manually and can not age out by themselves. Using static
MAC address entries can reduce broadcast packets remarkably and are suitable for networks
where network devices seldom change.
z Dynamic MAC address entry: This type of MAC address entries age out after the configured aging
time. They are generated by the MAC address learning mechanism or configured manually.
z Blackhole MAC address entry: This type of MAC address entries are configured manually. A switch
discards the packets destined for or originated from the MAC addresses contained in blackhole
MAC address entries.
Table 1-1 lists the different types of MAC address entries and their characteristics.
Table 1-1 Characteristics of different types of MAC address entries
MAC address entry Configuration method Aging time
Reserved or not at
reboot (if the
configuration is
saved)
Static MAC address
entry
Manually configured Unavailable Yes
Dynamic MAC address
entry
Manually configured or
generated by MAC address
learning mechanism
Available No
Blackhole MAC
address entry
Manually configured Unavailable Yes
Configuring MAC Address Table Management
Configuration Task List
Table 1-2 Configure MAC address table management
Task Remarks
Configuring a MAC Address Entry Required
Setting the Aging Time of MAC Address Entries Optional
Setting the Maximum Number of MAC Addresses a Port
Can Learn
Optional
Disabling MAC Address learning for a VLAN Optional