Cisco CPT Configuration Guide–CTC and Documentation Release 9.3 and Cisco IOS Release 15.1(01)SA
Configuring MAC Learning

Contents

Configuring MAC Learning

This chapter describes MAC learning, MAC address limiting, and static MAC address. This chapter also describes the configuration procedures.

Understanding MAC Learning

The Carrier Packet Transport (CPT) system is a distributed system with fabric cards, line cards, and CPT 50 panels. The MAC addresses learned on one line card needs to be learned or distributed on the other line cards. The MAC learning feature enables the distribution of the MAC addresses learned on one line card to the other line cards.

A software MAC address table is maintained on the fabric cards. This MAC address table contains the MAC addresses learned on all the line cards. This MAC address table is used to distribute the MAC addresses when the line card reboots or goes through Online Insertion and Removal (OIR).


Note


By default, MAC address learning is enabled only for point–to–multipoint bridge domains and can also be disabled. See NTP-J7 Enable or Disable MAC Learning on a Bridge Domain.


MAC Address Aging

Dynamically learned MAC addresses are deleted after the MAC address age out value. This frees up unused addresses from the MAC address table for other active subscribers. In CPT, the default value for MAC address aging is 300 seconds and cannot be changed. The expected MAC address age out timer is between 300 to 600 seconds depending on the number of MAC addresses learned.

Dynamic MAC Address Learning

Dynamic MAC address learning occurs when the bridging data path encounters an ingress frame whose source address is not present in the MAC address table for the ingress service instance. The learned MAC addresses are distributed to the other cards with Ethernet Flow Points (EFPs) in the same bridge domain.

MAC Move

A MAC move occurs when the same MAC address is re-learned on a different port. When a MAC move is detected, a transient event is generated to inform the user about the MAC move.

MAC Learning on LAG

MAC learning is enabled on the LAG interface, if the Link Aggregation Group (LAG) interface is part of the point–to–multipoint bridge domain. The MAC addresses are learned on the LAG interface instead of the physical interface.

MAC Learning Actions

The following table describes the various scenarios and the actions taken on MAC addresses for each scenario.

Table 1 MAC Learning Actions
Scenario Action
A bridge domain is created. The MAC learning is enabled by default in point–to–multipoint bridge domains. The MAC learning is not supported in point–to–point bridge domains.
A bridge domain is deleted. The MAC addresses learned on the bridge domain are removed from the software MAC address table that is maintained on the fabric cards. These MAC addresses are also removed from the line card hardware.
An EFP is added and is the first EFP on a bridge domain on a card. All the MAC addresses learned on the bridge domain are sent to this new card.
An EFP is added and is not the first EFP on a bridge domain. Nothing needs to be done as the MAC addresses learned on the bridge domain are already present.
An EFP is deleted. All the MAC addresses learned on that EFP are deleted.
An EFP admin state is UP. When the EFP is the first EFP on the bridge domain on the card, all the MAC addresses learned on the bridge domain are sent to this new card. When the EFP is not the first EFP on the bridge domain on the card, nothing needs to be done as the MAC addresses learned on the bridge domain are already present.
An EFP admin state is DOWN. All the MAC addresses learned on that EFP are deleted.
The port goes down. All the MAC addresses learned on the port on all the bridge domains are deleted.
The active fabric card is reset. The standby fabric card becomes active and the software MAC address table on the new active card is used.
The standby fabric card is reset. The standby fabric card is updated with the software MAC address table during the bulk synchronization process.
The line card comes up after the line card is reset (soft reset). The active fabric card sends the MAC addresses learned on the bridge domains that are configured on the line card.
The line card goes through Online Insertion and Removal (OIR). The active fabric card sends the MAC addresses learned on the bridge domains that are configured on the line card.

NTP-J7 Enable or Disable MAC Learning on a Bridge Domain

Purpose This procedure enables or disables MAC learning on a bridge domain.
Tools/Equipment None
Prerequisite Procedures None
Required/As Needed As needed
Onsite/Remote Onsite or remote
Security Level Provisioning or higher
Procedure

DLP-J19 Re–enable or Disable MAC Learning on a Bridge Domain Using Cisco IOS Commands

Purpose This procedure re-enables or disables MAC learning on the bridge domain using Cisco IOS commands.
Tools/Equipment None
Prerequisite Procedures None
Required/As Needed As needed
Onsite/Remote Onsite or remote
Security Level Provisioning or higher

Note


MAC learning is enabled on the point–to–multipoint bridge domains by default.


Procedure
     Command or ActionPurpose
    Step 1enable


    Example:Router> enable 

    Enables privileged EXEC mode.

    • Enter your password if prompted.
     
    Step 2configure terminal


    Example:Router# configure terminal 

    Enters global configuration mode.

     
    Step 3bridge-domain bridge-id


    Example:Router(config)# bridge-domain 100 

    Configures components on a bridge domain and enters bridge domain configuration mode.

     
    Step 4mac learning


    Example:Router(config-bdomain)# mac learning 

    Re-enables MAC learning on this bridge domain.

     
    Step 5no mac learning


    Example:Router(config-bdomain)# no mac learning 

    Disables MAC learning on this bridge domain.

     
    Step 6end


    Example:Router(config-bdomain)# end 

    Exits bridge domain configuration mode and returns to privileged EXEC mode.

     
    Step 7Return to your originating procedure (NTP). 

     

    Example: Re–enable or Disable MAC Learning on a Bridge Domain

    The following example shows how to re-enable MAC learning on a bridge domain using Cisco IOS commands:

    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 using Cisco IOS commands:

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

    DLP-J20 Re-enable or Disable MAC Learning on a Bridge Domain Using CTC

    Purpose This procedure re-enables or disables MAC learning on the bridge domain using CTC.
    Tools/Equipment None
    Prerequisite Procedures DLP-J2 Create an EVC Circuit Using CTC of EVC type Ethernet Private LAN or Ethernet Virtual Private LAN.
    Required/As Needed As needed
    Onsite/Remote Onsite or remote
    Security Level Provisioning or higher

    Note


    MAC learning is enabled on the point–to–multipoint bridge domains by default.


    Procedure
      Step 1   Complete the NTP-J22 Log into CTC procedure at a node where you want to re-enable or disable MAC learning.
      Step 2   From the View menu, choose Go to Home View.
      Step 3   Click the Layer2+ tab.
      Step 4   Click Carrier Ethernet.
      Step 5   From the list of EVC circuits, choose an EVC circuit to edit.
      Step 6   Click Edit. The Edit Circuit dialog box appears.
      Step 7   Click the MAC Learning tab.
      Step 8   Re-enable or disable MAC learning on the Network Element. Complete one of the following steps:
      1. Check the MAC Learning check box to re-enable MAC learning on this Network Element.
      2. Uncheck the MAC Learning check box to disable MAC learning on this Network Element.
      Step 9   Click Apply.
      Step 10   Return to your originating procedure (NTP).

      Understanding MAC Address Limiting

      The MAC Address Limiting for bridge domains provides the capability to control the MAC addresses learnt on the bridge domain. You can configure an upper limit on the number of MAC addresses that can be learnt in a bridge domain. If an Ethernet frame with an unknown MAC address is received, it is flooded in the bridge domain. The MAC address limiting commands are configured under the bridge domain.


      Note


      The maximum MAC address limit on a bridge domain is 128000.


      NTP-J8 Configure MAC Address Limit on a Bridge Domain

      Purpose

      This procedure configures MAC address limit on a bridge domain.

      Tools/Equipment None
      Prerequisite Procedures None
      Required/As Needed As needed
      Onsite/Remote Onsite or remote
      Security Level Provisioning or higher
      Procedure

      DLP-J21 Configure MAC Address Limit on a Bridge Domain Using Cisco IOS Commands

      Purpose This procedure configures an upper limit on the number of MAC addresses that reside in a bridge domain using Cisco IOS commands.
      Tools/Equipment None
      Prerequisite Procedures None
      Required/As Needed As needed
      Onsite/Remote Onsite or remote
      Security Level Provisioning or higher
      Procedure
         Command or ActionPurpose
        Step 1enable


        Example:Router> enable 

        Enables privileged EXEC mode.

        • Enter your password if prompted.
         
        Step 2configure terminal


        Example:Router# configure terminal 

        Enters global configuration mode.

         
        Step 3bridge-domain bridge-id


        Example:Router(config)# bridge-domain 100 

        Configures components on a bridge domain and enters bridge domain configuration mode.

         
        Step 4mac limit maximum addresses maximum-addresses


        Example:Router(config-bdomain)# mac limit maximum addresses 200 

        Sets an upper limit on the number of MAC addresses that reside in a bridge domain.

        Note   

        Enter the no mac limit command to restore the default MAC address limit.

         
        Step 5end


        Example:Router(config-bdomain)# end 

        Exits bridge domain configuration mode and returns to privileged EXEC mode.

         
        Step 6Return to your originating procedure (NTP). 

         

        Example: Configure MAC Address Limit on a Bridge Domain

        The following example shows how to configure MAC address limiting on a bridge domain using Cisco IOS commands:

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

        DLP-J22 Configure the MAC Address Limit on a Bridge Domain Using CTC

        Purpose This procedure configures the MAC address limit on a bridge domain using CTC.
        Tools/Equipment None
        Prerequisite Procedures DLP-J2 Create an EVC Circuit Using CTC of EVC type Ethernet Private LAN or Ethernet Virtual Private LAN.
        Required/As Needed As needed
        Onsite/Remote Onsite or remote
        Security Level Provisioning or higher
        Procedure
          Step 1   Complete the NTP-J22 Log into CTC procedure at a node where you want to configure the MAC address limit.
          Step 2   From the View menu, choose Go to Home View.
          Step 3   Click the Layer2+ tab.
          Step 4   Click Carrier Ethernet.
          Step 5   From the list of EVC circuits, select an EVC circuit to edit.
          Step 6   Click Edit. The Edit Circuit dialog box appears.
          Step 7   Click the MAC Learning tab.
          Step 8   Enter the upper limit on the number of MAC addresses that reside in a bridge domain in the Limit field.

          You need to change the MAC address limit value on each node where the bridge domain is configured.

          Step 9   Click Apply.
          Step 10   Return to your originating procedure (NTP).

          Understanding the Static MAC Address

          You can configure static MAC addresses on a service instance. Static MAC address configuration on service instances eliminates the need for MAC address learning, which is required for traffic forwarding. Without MAC address learning, MAC address table resources can be conserved and network resources can be optimized.


          Note


          Static MAC address configuration does not apply to the MVR bridge domain.


          Benefits

          Static MAC address support on service instances provides the following benefits:

          • Facilitates optimization of network resources.
          • Conserves MAC table resources when used for upstream traffic.

          Restrictions

          • Multicast static MAC addresses are not allowed in MAC address configurations. Unicast MAC addresses can be statically configured.

          NTP-J9 Configure a Static MAC Address on a Service Instance

          Purpose

          This procedure configures a static MAC address on a service instance.

          Tools/Equipment None
          Prerequisite Procedures None
          Required/As Needed As needed
          Onsite/Remote Onsite or remote
          Security Level Provisioning or higher
          Procedure

          DLP-J23 Configure a Static MAC Address on a Service Instance Using Cisco IOS Commands

          Purpose This procedure configures a static MAC address on a service instance using Cisco IOS commands.
          Tools/Equipment None
          Prerequisite Procedures DLP-J1 Configure an Ethernet Service Instance Using Cisco IOS Commands
          Required/As Needed As needed
          Onsite/Remote Onsite or remote
          Security Level Provisioning or higher

          Note


          Enter the no mac static address mac-addr command to remove the statically added unicast MAC address.


          Procedure
             Command or ActionPurpose
            Step 1enable


            Example:Router> enable 

            Enables privileged EXEC mode.

            • Enter your password if prompted.
             
            Step 2configure terminal


            Example:Router# configure terminal 

            Enters global configuration mode.

             
            Step 3interface type number


            Example:Router(config)# interface TenGigabitEthernet 4/1 

            Configures a Ten Gigabit Ethernet interface and enters interface configuration mode.

             
            Step 4service instance id ethernet [evc-id]


            Example:Router(config-if)# service instance 1 ethernet 

            Configures an Ethernet service instance on an interface and enters service instance configuration mode.

             
            Step 5mac static address mac-address


            Example:Router(config-if-srv)# mac static address 0000.bbbb.cccc 

            Configures a static MAC address on a service instance.

             
            Step 6exit


            Example:Router(config-if-srv)# exit 

            Returns to interface configuration mode.

             
            Step 7end


            Example:Router(config-if)# end 

            Returns to privileged EXEC mode.

             
            Step 8Return to your originating procedure (NTP). 

             

            Example: Configure a Static MAC Address on a Service Instance

            The following example shows how to configure a static MAC address on a service instance using Cisco IOS commands:

            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
            

            DLP-J24 Configure a Static MAC Address on a Service Instance Using CTC

            Purpose This procedure configures a static MAC address on a service instance using CTC.
            Tools/Equipment None
            Prerequisite Procedures DLP-J2 Create an EVC Circuit Using CTC of EVC type Ethernet Private LAN or Ethernet Virtual Private LAN.
            Required/As Needed As needed
            Onsite/Remote Onsite or remote
            Security Level Provisioning or higher
            Procedure
              Step 1   Complete the NTP-J22 Log into CTC procedure at a node where you want to configure a static MAC address.
              Step 2   From the View menu, choose Go to Home View.
              Step 3   Click the Layer2+ tab.
              Step 4   Click Carrier Ethernet.
              Step 5   From the list of EVC circuits, select an EVC circuit to edit.
              Step 6   Click Edit. The Edit Circuit dialog box appears.
              Step 7   Click the MAC Learning tab.
              Step 8   Click EFP Static MAC Address Configuration to enter static MAC addresses for each EFP. The EFP Static MAC Address Configuration dialog box appears.
              Step 9   From the EFP drop-down list, choose an EFP.
              Step 10   Enter one or more static MAC addresses for this EFP in the MAC Address field and click Add. The added MAC addresses appear in the Entered MAC Addresses area.
              Step 11   Click Apply and close the EFP Static MAC Address Configuration dialog box.
              Step 12   Return to your originating procedure (NTP).

              NTP-J10 Remove a MAC address

              Purpose This procedure removes a MAC address from the MAC address table.
              Tools/Equipment None
              Prerequisite Procedures None
              Required/As Needed As needed
              Onsite/Remote Onsite or remote
              Security Level Provisioning or higher
              Procedure
              Perform any of the following procedures as needed:

              Stop. You have completed this procedure.


              DLP-J25 Remove a MAC Address Using Cisco IOS Commands

              Purpose This procedure removes a dynamic MAC address from the MAC address table using Cisco IOS commands.
              Tools/Equipment None
              Prerequisite Procedures None
              Required/As Needed As needed
              Onsite/Remote Onsite or remote
              Security Level Provisioning or higher

              Note


              This procedure removes only dynamically added MAC addresses. To remove the statically added MAC addresses, enter the no mac static address mac-addr command.


              Procedure
                 Command or ActionPurpose
                Step 1enable


                Example:Router> enable 

                Enables privileged EXEC mode.

                • Enter your password if prompted.
                 
                Step 2configure terminal


                Example:Router# configure terminal 

                Enters global configuration mode.

                 
                Step 3clear mac-address-table [address mac-address] [interface type number] [bridge-domain bridgedomain-id]

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

                Removes the dynamic MAC address from the MAC address table on a bridge domain. The bridgedomain-id is the bridge domain number.

                 
                Step 4exit


                Example:Router# exit 

                Exits global configuration mode.

                 
                Step 5Return to your originating procedure (NTP). 

                 

                Example: Remove a MAC Address

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

                Router> enable
                Router# configure terminal
                Router# clear mac-address-table address 
                0000.bbbb.cccc interface TenGigabitEthernet 4/1 bridge-domain 100
                Router# exit
                

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

                Router> enable
                Router# configure terminal
                Router# clear mac-address-table address 0000.bbbb.cccc
                Router# exit
                

                DLP-J26 Remove a MAC Address Using CTC

                Purpose This procedure removes a specific MAC address from the MAC address table using CTC.
                Tools/Equipment None
                Prerequisite Procedures DLP-J2 Create an EVC Circuit Using CTC of EVC type Ethernet Private LAN or Ethernet Virtual Private LAN.
                Required/As Needed As needed
                Onsite/Remote Onsite or remote
                Security Level Provisioning or higher
                Procedure
                  Step 1   Complete the NTP-J22 Log into CTC procedure at a node where you want to remove specific MAC addresses from the MAC address table.
                  Step 2   From the View menu, choose Go to Home View.
                  Step 3   Click the Layer2+ tab.
                  Step 4   Click Carrier Ethernet.
                  Step 5   From the list of EVC circuits, select an EVC circuit to edit.
                  Step 6   Click Edit. The Edit Circuit dialog box appears.
                  Step 7   Click the MAC Learning tab.
                  Step 8   Click Clear MAC Addresses. The Clear MAC Addresses dialog box appears.
                  Step 9   To remove a specific MAC address from the MAC address table, select that MAC address in the MAC Addresses to clear area and click Clear.
                  Step 10   Close the Clear MAC Addresses dialog box.
                  Step 11   Return to your originating procedure (NTP).

                  NTP-J11 Display Information About the MAC Address Table

                  Purpose

                  This procedure displays information about the MAC address table.

                  Tools/Equipment None
                  Prerequisite Procedures None
                  Required/As Needed As needed
                  Onsite/Remote Onsite or remote
                  Security Level Provisioning or higher
                  Procedure

                  DLP-J27 Display Information About the MAC Address Table Using Cisco IOS Commands

                  Purpose This procedure displays information about the MAC address table using Cisco IOS commands.
                  Tools/Equipment None
                  Prerequisite Procedures None
                  Required/As Needed As needed
                  Onsite/Remote Onsite or remote
                  Security Level Provisioning or higher
                  Procedure
                     Command or ActionPurpose
                    Step 1enable


                    Example:Router> enable 

                    Enables privileged EXEC mode.

                    • Enter your password if prompted.
                     
                    Step 2show mac-address-table address mac-addr


                    Example:Router# show mac-address-table address 0050.3e8d.6400 

                    Displays information about the MAC address table for a specific MAC address. The mac-addr is a 48–bit MAC address and the valid format is H.H.H.

                     
                    Step 3show mac-address-table bridge-domain bridgedomain-id


                    Example:Router# show mac-address-table bridge-domain 100 

                    Displays information about the MAC address table for a specific bridge domain. The bridgedomain-id is the bridge domain number.

                     
                    Step 4show mac-address-table interface type number


                    Example:Router# show mac-address-table interface TenGigabitEthernet 4/1 

                    Displays information about the MAC address table for a specific interface.

                     
                    Step 5Return to your originating procedure (NTP). 

                     

                    Example: Display Information About the MAC Address Table

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

                    Router# show mac-address-table
                    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
                    200        0050.3e8d.6400   static    Te4/1
                    100        0050.3e8d.6400   static    Te4/1
                    5          0050.3e8d.6400   static    Te4/1
                    4          0050.3e8d.6400   static    Te4/1
                    1	         0050.3e8d.6400   static    Te4/1
                    

                    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
                    

                    The following example shows how to display the MAC address table information for a LAG interface (Po9):

                    Router# show mac-address-table
                    BD index   MAC Address     Type    Ports
                    --------------------------------------------
                    2         0000.0300.0900  dynamic  Te4/1
                    2         0000.0300.1000  dynamic  Po9
                    

                    DLP-J28 Display Information About the MAC Address Table Using CTC

                    Purpose This procedure displays information about the MAC address table using CTC.
                    Tools/Equipment None
                    Prerequisite Procedures None
                    Required/As Needed As needed
                    Onsite/Remote Onsite or remote
                    Security Level Provisioning or higher
                    Procedure
                      Step 1   Complete the NTP-J22 Log into CTC procedure at a node where you want to display information about the MAC address table.
                      Step 2   From the View menu, choose Go to Home View.
                      Step 3   Right-click the fabric or line card and choose Open Packet Transport System View. The Packet Transport System View dialog box appears.
                      Step 4   Click the Maintenance tab.
                      Step 5   From the left pane, click MAC Learning.
                      Step 6   To display information about the MAC address table for a specific MAC address:
                      1. Click the MAC Addresses subtab.
                      2. Enter the MAC address in the MAC address field.
                      3. Click Show to display information about the MAC address table for this MAC address.
                      Step 7   To display information about the MAC address table for a specific interface:
                      1. Click the Interface subtab.
                      2. From the Interface type drop-down list, choose ONE_GE, TEN_GE, or PORT_CHANNEL.
                      3. Enter the interface number in the Interface Number field.
                      4. Click Show to display information about the MAC address table for this interface.
                      Step 8   To display information about the MAC address table for a specific EFP:
                      1. From the View menu, choose Go to Home View
                      2. Click the Layer2+ tab.
                      3. Click Carrier Ethernet.
                      4. From the list of EVC circuits, select an EVC circuit to edit.
                      5. Click Edit. The Edit Circuit dialog box appears.
                      6. Click the MAC Learning tab.
                      7. Click Display MAC Address(es) to display the configured static MAC addresses for each EFP. The Configured EFP Static MAC Addresses dialog box appears.
                      8. From the EFP drop-down list, choose an EFP.
                      9. The MAC addresses configured on the EFP appear in the Configured MAC Addresses area.
                      10. Close the Configured EFP Static MAC Addresses dialog box.
                      Step 9   Return to your originating procedure (NTP).