Default Mac Address Table Configuration - Cisco Catalyst 4500 Series Configuration Manual

Chapter 4 Administering the Switch
When PVLANs are configured, address learning depends on the type of MAC address:
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For more information about PVLANs, see

Default MAC Address Table Configuration

Table 4-3
Table 4-3
Feature
Aging time
Dynamic addresses
Static addresses
Changing the Address Aging Time
Dynamic addresses are source MAC addresses that the switch learns and then ages when they are not in
use. You can change the aging time setting for all VLANs or for a specified VLAN.
Setting too short an aging time can cause addresses to be prematurely removed from the table. When the
switch receives a packet for an unknown destination, it floods the packet to all ports in the same VLAN
as the receiving port. This unnecessary flooding can impact performance. Setting too long an aging time
can cause the address table to be filled with unused addresses, which prevents new addresses from being
learned. Flooding results, which can impact switch performance.
To configure the dynamic address table aging time, perform this task:
Command
Step 1
configure terminal
Step 2
mac address-table aging-time
] [
10-1000000 vlan vlan-id
Step 3
end
OL-25340-01
Dynamic MAC addresses learned in one VLAN of a PVLAN are replicated in the associated
VLANs. For example, a MAC address learned in a private-VLAN secondary VLAN is replicated in
the primary VLAN.
Static MAC addresses configured in a primary or secondary VLAN are not replicated in the
associated VLANs. When you configure a static MAC address in a PVLAN primary or secondary
VLAN, you should also configure the same static MAC address in all associated VLANs.
shows the default MAC address table configuration.
Default MAC Address Table Configuration
[ |
0
]
Chapter 42, "Configuring Private VLANs."
Default Setting
300 seconds
Automatically learned
None configured
Purpose
Enters global configuration mode.
Sets the length of time that a dynamic entry remains in the MAC
address table after the entry is used or updated.
To return to the default value, use the no mac address-table
aging-time global configuration command.
The range is 10 to 1000000 seconds. The default is 300. You can also
enter 0, which disables aging. Static address entries are never aged
or removed from the table.
For vlan-id, valid IDs are 1 to 4094.
Returns to privileged EXEC mode.
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
Managing the MAC Address Table
4-23