Contents

• MAC Learning Command Reference

• clear mac-address-table

• mac learning

• mac limit maximum addresses

• mac static address

• show mac-address-table

MAC Learning Command Reference

---

This chapter describes commands to configure MAC learning.

• clear mac-address-table
• mac learning
• mac limit maximum addresses
• mac static address
• show mac-address-table

clear mac-address-table

To remove a specified address (or set of addresses) from the MAC address table, use the clear mac-address-table command in privileged EXEC mode.

clear mac-address-table [ address mac-addr] [ bridge-domain bridgedomain-id] [ interface type number]

Syntax Description

address mac-addr	(Optional) Specifies the MAC address to clear.
bridge-domain bridgedomain-id	(Optional) Clears the MAC address from the specified bridge domain.
interface type number	(Optional) Clears the MAC address from the specified interface.

Command Default

When no options are specified, all the dynamically added MAC addresses are cleared.

Command Modes

Privileged EXEC (#)

Command History

Release	Modification
9.3.0	This command was introduced.

Usage Guidelines

If the clear mac-address-table command is used without options, all the MAC addresses are removed. If you specify an address but do not specify an interface, the address is deleted from all the interfaces. If you specify an interface but do not specify an address, all the addresses on the specified interface are removed.

Examples

The following example shows how to remove a MAC address from the MAC address table on a bridge domain:

Router# clear mac-address-table address 
0000.bbbb.cccc interface TenGigabitEthernet 4/1 bridge-domain 100

The following example shows how to remove a MAC address from the MAC address table on all the bridge domains:

Router# clear mac-address-table address 0000.bbbb.cccc

Related Commands

Command	Description
show mac-address-table	Displays information about the MAC address table.

mac learning

To reenable MAC learning on the bridge domain, use the mac learning command in bridge domain configuration mode. To disable MAC learning, use the no form of this command.

mac learning

no mac learning

Syntax Description

This command has no arguments or keywords.

Command Default

MAC learning is enabled on the bridge domains by default.

Command Modes

Bridge domain configuration (config-bdomain)

Command History

Release	Modification
9.3.0	This command was introduced.

Usage Guidelines

MAC address learning is enabled by default only for point–to–multipoint bridge domains and can also be disabled.

Examples

The following example shows how to reenable MAC learning on a bridge domain:

Router> enable
Router# configure terminal
Router(config)# bridge-domain 100
Router(config-bdomain)# mac learning
Router(config-bdomain)# end

The following example shows how to disable MAC learning on a bridge domain:

Router> enable
Router# configure terminal
Router(config)# bridge-domain 100
Router(config-bdomain)# no mac learning
Router(config-bdomain)# end

Related Commands

Command	Description
mac static address	Configures a static MAC address on a service instance.
mac limit maximum addresses	Configures the maximum number of MAC addresses allowed on a bridge domain.

mac limit maximum addresses

To configure the maximum number of MAC addresses allowed on a bridge domain, use the mac limit maximum addresses command in bridge domain configuration mode. To return to the default state, use the no form of this command.

mac limit maximum addresses maximum-addresses

no mac limit maximum addresses maximum-addresses

Syntax Description

maximum-addresses

Integer that specifies the maximum number of MAC addresses allowed on a bridge domain. The range is from 1 to 128000.

Command Default

Maximum number of MAC addresses are allowed on the bridge domain.

Command Modes

Bridge domain configuration (config-bdomain)

Command History

Release	Modification
9.3.0	This command was introduced.

Examples

The following example shows how to set the maximum number of MAC addresses on a specific bridge domain to 1000:

Router> enable
Router# configure terminal
Router(config)# bridge-domain 100
Router(config-bdomain)# mac limit maximum addresses 1000
Router(config-bdomain)# end

Related Commands

Command	Description
mac learning	Enables MAC learning on a bridge domain.

mac static address

To configure a static MAC address on a service instance, use the mac static address command in service instance configuration mode. To remove a static MAC address, use the no form of this command.

mac static address mac-addr

no mac static address mac-addr

Syntax Description

mac-addr

The 48-bit static MAC address.

Command Default

MAC static addresses are not configured.

Command Modes

Service instance configuration (config-if-srv)

Command History

Release	Modification
9.3.0	This command was introduced.

Usage Guidelines

Static MAC address configuration is supported only on Ethernet virtual circuit (EVC) bridge domain interfaces. The static MAC address configuration does not apply to the Multicast VLAN Registration (MVR) bridge domain.

Examples

The following example shows how to configure a MAC static address in service instance configuration mode:

Router> enable
Router# configure terminal
Router(config)# interface TenGigabitEthernet 4/1
Router(config-if)# service instance 1 ethernet
Router(config-if-srv)# encapsulation dot1q 100
Router(config-if-srv)# bridge-domain 100
Router(config-if-srv)# mac static address 0000.bbbb.cccc
Router(config-if-srv)# exit
Router(config-if)# end

Related Commands

Command	Description
mac learning	Enables MAC learning on a bridge domain.

show mac-address-table

To display information about the MAC address table, use the show mac-address-table command in privileged EXEC mode.

show mac-address-table [ address mac-addr] [ bridge-domain bridgedomain-id] [ interface type number] [ count]

Syntax Description

address mac-addr	(Optional) Displays information about the MAC address table for a specific MAC address.
bridge-domain bridgedomain-id	(Optional) Displays information about the MAC address table for a specific bridge domain.
interface type number	(Optional) Displays information about the MAC address table for a specific interface.
count	(Optional) Displays the number of entries that are currently in the MAC address table.

Command Default

When no options are specified, the command displays the entire MAC address table.

Command Modes

Privileged EXEC (#)

Command History

Release	Modification
9.3.0	This command was introduced.

Usage Guidelines

The mac-addr is a 48–bit MAC address and the valid format is H.H.H. The bridgedomain-id is the bridge domain number.

Examples

The following example shows how to display the MAC address table information for a specific MAC address:

Router# show mac-address-table address 0000.1000.0001

BD Index   MAC Address     Type     Ports
--------------------------------------------
 2         0000.1000.0001  dynamic   Te4/2            

The following example shows how to display the MAC address table information for a specific bridge domain:

Router# show mac-address-table bridge-domain 2

BD Index   MAC Address     Type    Ports
--------------------------------------------
2         0000.1000.001e   dynamic  Te4/2
2         0000.1000.001d   dynamic  Te4/2
2         0000.1000.001c   dynamic  Te4/2
2         0000.1000.001b   dynamic  Te4/2
2         0000.1000.001a   dynamic  Te4/2
2         0000.1000.0019   dynamic  Te4/2 

The following example shows how to display the MAC address table information for a specific interface:

Router# show mac-address-table interface tenGigabitEthernet4/2

BD Index   MAC Address     Type    Ports
--------------------------------------------
2         0000.1000.001e  dynamic    Te4/2
2         0000.1000.001d  dynamic    Te4/2
2         0000.1000.001c  dynamic    Te4/2
2         0000.1000.001b  dynamic    Te4/2
2         0000.1000.001a  dynamic    Te4/2
2         0000.1000.0019  dynamic    Te4/2

Related Commands

Command	Description
clear mac-address-table	Deletes entries from the MAC address table.