Specifications

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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
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Chapter 8 Administering the Switch
Managing the MAC Address Table
Adding and Removing Secure Addresses
A secure address is a manually entered unicast address or dynamically learned address that is forwarded
to only one port per VLAN. If you enter a static address that is already assigned to another port, the
request will be rejected.
Secure addresses can be learned dynamically if the configured secure addresses do not reach the
maximum limit of the port.
You can configure an interface to convert the dynamic MAC addresses to sticky secure MAC addresses
and to add them to the running configuration by enabling sticky learning. When sticky learning is
enabled, the interface converts all the dynamic secure MAC addresses, including those that were learned
dynamically before sticky learning is enabled, to sticky secure MAC addresses. It adds all the sticky
secure MAC addresses to the running configuration. For more information, see the “Secure MAC
Addresses” section on page 19-4.
Beginning in privileged EXEC mode, follow these steps to add a secure address:
To remove a secure address, use the no switchport port-security mac-address mac-address global
configuration command.
Displaying Address Table Entries
You can display the MAC address table by using one or more of the privileged EXEC commands
described in Table 8-4:
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Specify an interface, and enter interface configuration mode.
Step 3
switchport port-security
mac-address mac-address
Add a secure address.
Step 4
end Return to privileged EXEC mode.
Step 5
show port-security Verify your entry.
Step 6
copy running-config
startup-config
(Optional) Save your entries in the configuration file.
Table 8-4 Commands for Displaying the MAC Address Table
Command Description
show mac address-table address Displays MAC address table information for the specified MAC address.
show mac address-table aging-time Displays the aging time in all VLANs or the specified VLAN.
show mac address-table count Displays the number of addresses present in all VLANs or the specified VLAN.
show mac address-table dynamic Displays dynamic MAC address table entries only.
show mac address-table interface Displays the MAC address table information for the specified interface.
show mac address-table multicast Displays the Layer 2 multicast entries for all VLANs or the specified VLAN.
show mac address-table static Displays static MAC address table entries only.
show mac address-table vlan Displays the MAC address table information for the specified VLAN.