3Com 4210 PWR - Configuring MAC Address Table Management

134 CHAPTER 13: MAC ADDRESS TABLE MANAGEMENT
n
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:
■ 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.
■ 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.
■ 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 88 lists the different types of MAC address entries and their characteristics.
Configuring MAC
Address Table
Management
MAC Address Table
Management
Configuration Tasks
Tabl e 88 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
Tabl e 89 Configure MAC address table management
Operation Description Related section
Configure a MAC address
entry
Required “Configuring a MAC Address
Entry”.
Set the aging time of MAC
address entries
Optional “Setting the Aging Time of
MAC Address Entries”.
Set the maximum number of
MAC addresses a port can
learn
Optional “Setting the Maximum
Number of MAC Addresses a
Port Can Learn”.