H3C Technologies H3C S3100 Series Switches - Manual (Page 169)

Operation Manual – MAC Address Table
H3C S3100-52P Ethernet Switch
Chapter 1 MAC Address Table
Management
1-3
Note:
The switch learns only unicast addresses by using the MAC address learning
mechanism but directly drops any packet with a broadcast source MAC address.
1.1.2 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
1.2 Configuring MAC Address Table Management
The configuration to manage a MAC address table includes:
z
Configuring a MAC address entry
z
Configuring the aging time of MAC address entries