Configuring IGMP Snooping

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Restrictions for IGMP Snooping

The following are the restrictions for IGMP snooping:

  • The switch supports homogeneous stacking and mixed stacking. Mixed stacking is supported only with the Catalyst 2960-S switches. A homogenous stack can have up to eight stack members, while a mixed stack can have up to four stack members. All switches in a switch stack must be running the LAN Base image.

Information About IGMP Snooping

IGMP Snooping

Layer 2 switches can use IGMP snooping to constrain the flooding of multicast traffic by dynamically configuring Layer 2 interfaces so that multicast traffic is forwarded to only those interfaces associated with IP multicast devices. As the name implies, IGMP snooping requires the LAN switch to snoop on the IGMP transmissions between the host and the router and to keep track of multicast groups and member ports. When the switch receives an IGMP report from a host for a particular multicast group, the switch adds the host port number to the forwarding table entry; when it receives an IGMP Leave Group message from a host, it removes the host port from the table entry. It also periodically deletes entries if it does not receive IGMP membership reports from the multicast clients.


Note

For more information on IP multicast and IGMP, see RFC 1112 and RFC 2236.

The multicast router sends out periodic general queries to all VLANs. All hosts interested in this multicast traffic send join requests and are added to the forwarding table entry. The switch creates one entry per VLAN in the IGMP snooping IP multicast forwarding table for each group from which it receives an IGMP join request.

The switch supports IP multicast group-based bridging, instead of MAC-addressed based groups. With multicast MAC address-based groups, if an IP address being configured translates (aliases) to a previously configured MAC address or to any reserved multicast MAC addresses (in the range 224.0.0.xxx), the command fails. Because the switch uses IP multicast groups, there are no address aliasing issues.

The IP multicast groups learned through IGMP snooping are dynamic. However, you can statically configure multicast groups by using the ip igmp snooping vlan vlan-id static ip_address interface interface-id global configuration command. If you specify group membership for a multicast group address statically, your setting supersedes any automatic manipulation by IGMP snooping. Multicast group membership lists can consist of both user-defined and IGMP snooping-learned settings.


Note

You can manage IP multicast group addresses through features such as IGMP snooping and Multicast VLAN Registration (MVR), or by using static IP addresses. For information about MVR, see the next chapter.

You can configure an IGMP snooping querier to support IGMP snooping in subnets without multicast interfaces because the multicast traffic does not need to be routed.

If a port spanning tree, a port group, or a VLAN ID change occurs, the IGMP snooping-learned multicast groups from this port on the VLAN are deleted.

IGMP Versions

The switch supports IGMP Version 1, IGMP Version 2, and IGMP Version 3. These versions are interoperable on the switch. For example, if IGMP snooping is enabled on an IGMPv2 switch and the switch receives an IGMPv3 report from a host, the switch can forward the IGMPv3 report to the multicast router.


Note

The switch supports IGMPv3 snooping based only on the destination multicast MAC address. It does not support snooping based on the source MAC address or on proxy reports.

An IGMPv3 switch supports Basic IGMPv3 Snooping Support (BISS), which includes support for the snooping features on IGMPv1 and IGMPv2 switches and for IGMPv3 membership report messages. BISS constrains the flooding of multicast traffic when your network includes IGMPv3 hosts. It constrains traffic to approximately the same set of ports as the IGMP snooping feature on IGMPv2 or IGMPv1 hosts.


Note

IGMPv3 join and leave messages are not supported on switches running IGMP filtering or MVR.

An IGMPv3 switch can receive messages from and forward messages to a device running the Source Specific Multicast (SSM) feature.

Joining a Multicast Group

Figure 1. Initial IGMP Join Message.

When a host connected to the switch wants to join an IP multicast group and it is an IGMP version 2 client, it sends an unsolicited IGMP join message, specifying the IP multicast group to join. Alternatively, when the switch receives a general query from the router, it forwards the query to all ports in the VLAN. IGMP version 1 or version 2 hosts wanting to join the multicast group respond by sending a join message to the switch. The switch CPU creates a multicast forwarding-table entry for the group if it is not already present. The CPU also adds the interface where the join message was received to the forwarding-table entry. The host associated with that interface receives multicast traffic for that multicast group.



Router A sends a general query to the switch, which forwards the query to ports 2 through 5, all of which are members of the same VLAN. Host 1 wants to join multicast group 224.1.2.3 and multicasts an IGMP membership report (IGMP join message) to the group. The switch CPU uses the information in the IGMP report to set up a forwarding-table entry that includes the port numbers connected to Host 1 and to the router.

Table 1 IGMP Snooping Forwarding Table

Destination Address

Type of Packet

Ports

224.1.2.3

IGMP

1, 2

The switch hardware can distinguish IGMP information packets from other packets for the multicast group. The information in the table tells the switching engine to send frames addressed to the 224.1.2.3 multicast IP address that are not IGMP packets to the router and to the host that has joined the group.

Figure 2. Second Host Joining a Multicast Group. If another host (for example, Host 4) sends an unsolicited IGMP join message for the same group, the CPU receives that message and adds the port number of Host 4 to the forwarding table. Because the forwarding table directs IGMP messages only to the CPU, the message is not flooded to other ports on the switch. Any known multicast traffic is forwarded to the group and not to the CPU.

Table 2 Updated IGMP Snooping Forwarding Table

Destination Address

Type of Packet

Ports

224.1.2.3

IGMP

1, 2, 5

Related Tasks
Configuring a Host Statically to Join a Group
Related References
Example: Statically Configuring a Host on a Port

Leaving a Multicast Group

The router sends periodic multicast general queries, and the switch forwards these queries through all ports in the VLAN. Interested hosts respond to the queries. If at least one host in the VLAN wants to receive multicast traffic, the router continues forwarding the multicast traffic to the VLAN. The switch forwards multicast group traffic only to those hosts listed in the forwarding table for that IP multicast group maintained by IGMP snooping.

When hosts want to leave a multicast group, they can silently leave, or they can send a leave message. When the switch receives a leave message from a host, it sends a group-specific query to learn if any other devices connected to that interface are interested in traffic for the specific multicast group. The switch then updates the forwarding table for that MAC group so that only those hosts interested in receiving multicast traffic for the group are listed in the forwarding table. If the router receives no reports from a VLAN, it removes the group for the VLAN from its IGMP cache.

Immediate Leave

The switch uses IGMP snooping Immediate Leave to remove from the forwarding table an interface that sends a leave message without the switch sending group-specific queries to the interface. The VLAN interface is pruned from the multicast tree for the multicast group specified in the original leave message. Immediate Leave ensures optimal bandwidth management for all hosts on a switched network, even when multiple multicast groups are simultaneously in use.

Immediate Leave is only supported on IGMP version 2 hosts. IGMP version 2 is the default version for the switch.


Note

You should use the Immediate Leave feature only on VLANs where a single host is connected to each port. If Immediate Leave is enabled on VLANs where more than one host is connected to a port, some hosts may be dropped inadvertently.

Related Tasks
Enabling IGMP Immediate Leave
Related References
Example: Enable Immediate Leave on a VLAN

IGMP Configurable-Leave Timer

You can configure the time that the switch waits after sending a group-specific query to determine if hosts are still interested in a specific multicast group. The IGMP leave response time can be configured from 100 to 32767 milliseconds.

Related Tasks
Configuring the IGMP Leave Timer

IGMP Report Suppression


Note

IGMP report suppression is supported only when the multicast query has IGMPv1 and IGMPv2 reports. This feature is not supported when the query includes IGMPv3 reports.

The switch uses IGMP report suppression to forward only one IGMP report per multicast router query to multicast devices. When IGMP report suppression is enabled (the default), the switch sends the first IGMP report from all hosts for a group to all the multicast routers. The switch does not send the remaining IGMP reports for the group to the multicast routers. This feature prevents duplicate reports from being sent to the multicast devices.

If the multicast router query includes requests only for IGMPv1 and IGMPv2 reports, the switch forwards only the first IGMPv1 or IGMPv2 report from all hosts for a group to all the multicast routers.

If the multicast router query also includes requests for IGMPv3 reports, the switch forwards all IGMPv1, IGMPv2, and IGMPv3 reports for a group to the multicast devices.

If you disable IGMP report suppression, all IGMP reports are forwarded to the multicast routers.

Related Tasks
Disabling IGMP Report Suppression

IGMP Snooping and Switch Stacks

IGMP snooping functions across the switch stack; that is, IGMP control information from one switch is distributed to all switches in the stack. Regardless of the stack member through which IGMP multicast data enters the stack, the data reaches the hosts that have registered for that group.

If a switch in the stack fails or is removed from the stack, only the members of the multicast group that are on that switch will not receive the multicast data. All other members of a multicast group on other switches in the stack continue to receive multicast data streams. However, multicast groups that are common for both Layer 2 and Layer 3 (IP multicast routing) might take longer to converge if the active switch is removed.

Related Tasks
Configuring the IGMP Snooping Querier
Related References
Example: Setting the IGMP Snooping Querier Source Address
Example: Setting the IGMP Snooping Querier Maximum Response Time
Example: Setting the IGMP Snooping Querier Timeout
Example: Setting the IGMP Snooping Querier Feature

IGMP Filtering and Throttling

In some environments, for example, metropolitan or multiple-dwelling unit (MDU) installations, you might want to control the set of multicast groups to which a user on a switch port can belong. You can control the distribution of multicast services, such as IP/TV, based on some type of subscription or service plan. You might also want to limit the number of multicast groups to which a user on a switch port can belong.

With the IGMP filtering feature, you can filter multicast joins on a per-port basis by configuring IP multicast profiles and associating them with individual switch ports. An IGMP profile can contain one or more multicast groups and specifies whether access to the group is permitted or denied. If an IGMP profile denying access to a multicast group is applied to a switch port, the IGMP join report requesting the stream of IP multicast traffic is dropped, and the port is not allowed to receive IP multicast traffic from that group. If the filtering action permits access to the multicast group, the IGMP report from the port is forwarded for normal processing. You can also set the maximum number of IGMP groups that a Layer 2 interface can join.

IGMP filtering controls only group-specific query and membership reports, including join and leave reports. It does not control general IGMP queries. IGMP filtering has no relationship with the function that directs the forwarding of IP multicast traffic. The filtering feature operates in the same manner whether CGMP or MVR is used to forward the multicast traffic.

IGMP filtering applies only to the dynamic learning of IP multicast group addresses, not static configuration.

With the IGMP throttling feature, you can set the maximum number of IGMP groups that a Layer 2 interface can join. If the maximum number of IGMP groups is set, the IGMP snooping forwarding table contains the maximum number of entries, and the interface receives an IGMP join report, you can configure an interface to drop the IGMP report or to replace the randomly selected multicast entry with the received IGMP report.


Note

IGMPv3 join and leave messages are not supported on switches running IGMP filtering.

Related Tasks
Configuring the IGMP Throttling Action

Default IGMP Snooping Configuration

This table displays the default IGMP snooping configuration for the switch.

Table 3 Default IGMP Snooping Configuration

Feature

Default Setting

IGMP snooping

Enabled globally and per VLAN

Multicast routers

None configured

Multicast router learning (snooping) method

PIM-DVMRP

IGMP snooping Immediate Leave

Disabled

Static groups

None configured

TCN1 flood query count

2

TCN query solicitation

Disabled

IGMP snooping querier

Disabled

IGMP report suppression

Enabled

1 (1) TCN = Topology Change Notification

Default IGMP Filtering and Throttling Configuration

This table displays the default IGMP filtering and throttling configuration for the switch.

Table 4 Default IGMP Filtering Configuration

Feature

Default Setting

IGMP filters

None applied.

IGMP maximum number of IGMP groups

No maximum set.

Note   

When the maximum number of groups is in the forwarding table, the default IGMP throttling action is to deny the IGMP report.

IGMP profiles

None defined.

IGMP profile action

Deny the range addresses.

How to Configure IGMP Snooping

Enabling or Disabling IGMP Snooping on a Switch

When IGMP snooping is globally enabled or disabled, it is also enabled or disabled in all existing VLAN interfaces. IGMP snooping is enabled on all VLANs by default, but can be enabled and disabled on a per-VLAN basis.

Global IGMP snooping overrides the VLAN IGMP snooping. If global snooping is disabled, you cannot enable VLAN snooping. If global snooping is enabled, you can enable or disable VLAN snooping.

Follow these steps to globally enable IGMP snooping on the switch:

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    ip igmp snooping

    4.    end

    5.    copy running-config startup-config


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example: 
    Switch> enable
     

    Enables privileged EXEC mode. Enter your password if prompted.

     

    Step 2configure terminal


    Example: 
    
Switch# configure terminal
     

    Enters the global configuration mode.

     
    Step 3ip igmp snooping


    Example: 
    
Switch(config)# ip igmp snooping
     

    Globally enables IGMP snooping in all existing VLAN interfaces.

    Note   

    To globally disable IGMP snooping on all VLAN interfaces, use the no ip igmp snooping global configuration command.

     
    Step 4end


    Example: 
    
Switch(config)# end
     

    Returns to privileged EXEC mode.

     
    Step 5copy running-config startup-config


    Example: 
    Switch# copy running-config startup-config
     

    (Optional) Saves your entries in the configuration file.

     

    Enabling or Disabling IGMP Snooping on a VLAN Interface

    Follow these steps to enable IGMP snooping on a VLAN interface:

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    ip igmp snooping vlan vlan-id

      4.    end

      5.    copy running-config startup-config


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 enable


      Example: 
      Switch> enable
       

      Enables privileged EXEC mode. Enter your password if prompted.

       

      Step 2configure terminal


      Example: 
      
Switch# configure terminal
       

      Enters the global configuration mode.

       
      Step 3ip igmp snooping vlan vlan-id


      Example: 
      
Switch(config)# ip igmp snooping vlan 7
       

      Enables IGMP snooping on the VLAN interface. The VLAN ID range is 1 to 1001 and 1006 to 4094.

      IGMP snooping must be globally enabled before you can enable VLAN snooping.

      Note   

      To disable IGMP snooping on a VLAN interface, use the no ip igmp snooping vlan vlan-id global configuration command for the specified VLAN number.

       
      Step 4end


      Example: 
      
Switch(config)# end
       

      Returns to privileged EXEC mode.

       
      Step 5copy running-config startup-config


      Example: 
      Switch# copy running-config startup-config
       

      (Optional) Saves your entries in the configuration file.

       

      Setting the Snooping Method

      Multicast-capable router ports are added to the forwarding table for every Layer 2 multicast entry. The switch learns of the ports through one of these methods:

      • Snooping on IGMP queries, Protocol-Independent Multicast (PIM) packets, and Distance Vector Multicast Routing Protocol (DVMRP) packets.

      • Listening to Cisco Group Management Protocol (CGMP) packets from other routers.

      • Statically connecting to a multicast router port using the ip igmp snooping mrouter global configuration command.

      You can configure the switch either to snoop on IGMP queries and PIM/DVMRP packets or to listen to CGMP self-join or proxy-join packets. By default, the switch snoops on PIM/DVMRP packets on all VLANs. To learn of multicast router ports through only CGMP packets, use the ip igmp snooping vlan vlan-id mrouter learn cgmp global configuration command. When this command is entered, the router listens to only CGMP self-join and CGMP proxy-join packets and to no other CGMP packets. To learn of multicast router ports through only PIM-DVMRP packets, use the ip igmp snooping vlan vlan-id mrouter learn pim-dvmrp global configuration command.

      If you want to use CGMP as the learning method and no multicast routers in the VLAN are CGMP proxy-enabled, you must enter the ip cgmp router-only command to dynamically access the router.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    ip igmp snooping vlan vlan-id mrouter learn {cgmp | pim-dvmrp }

        4.    end

        5.    show ip igmp snooping

        6.    copy running-config startup-config


      DETAILED STEPS
         Command or ActionPurpose
        Step 1 enable


        Example: 
        Switch> enable
         

        Enables privileged EXEC mode. Enter your password if prompted.

         

        Step 2configure terminal


        Example: 
        
Switch# configure terminal
         

        Enters the global configuration mode.

         
        Step 3ip igmp snooping vlan vlan-id mrouter learn {cgmp | pim-dvmrp }


        Example: 
        Switch(config)# ip igmp snooping 
vlan 1 mrouter learn cgmp
         

        Specifies the multicast router learning method:

        • cgmp—Listens for CGMP packets. This method is useful for reducing control traffic.

        • pim-dvmrp—Snoops on IGMP queries and PIM-DVMRP packets. This is the default.

        Note   

        To return to the default learning method, use the no ip igmp snooping vlan vlan-id mrouter learn cgmp global configuration command.

         

        Step 4end


        Example: 
        
Switch(config)# end
         

        Returns to privileged EXEC mode.

         
        Step 5show ip igmp snooping


        Example: 
        
Switch# show ip igmp snooping
         

        Verifies the configuration.

         
        Step 6copy running-config startup-config


        Example: 
        Switch# copy running-config startup-config
         

        (Optional) Saves your entries in the configuration file.

         
        Related References
        Example: Configuring IGMP Snooping Using CGMP Packets

        Configuring a Multicast Router Port

        Perform these steps to add a multicast router port (enable a static connection to a multicast router) on the switch.


        Note

        Static connections to multicast routers are supported only on switch ports.

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    ip igmp snooping vlan vlan-id mrouter interface interface-id

          4.    end

          5.    show ip igmp snooping mrouter [vlan vlan-id]

          6.    copy running-config startup-config


        DETAILED STEPS
           Command or ActionPurpose
          Step 1 enable


          Example: 
          Switch> enable
           

          Enables privileged EXEC mode. Enter your password if prompted.

           

          Step 2configure terminal


          Example: 
          
Switch# configure terminal
           

          Enters the global configuration mode.

           
          Step 3ip igmp snooping vlan vlan-id mrouter interface interface-id


          Example: 
          
Switch(config)# ip igmp snooping vlan 5 mrouter interface gigabitethernet1/0/1
           

          Specifies the multicast router VLAN ID and the interface to the multicast router.

          • The VLAN ID range is 1 to 1001 and 1006 to 4094.

          • The interface can be a physical interface or a port channel. The port-channel range is 1 to 128.

          Note   

          To remove a multicast router port from the VLAN, use the no ip igmp snooping vlan vlan-id mrouter interface interface-id global configuration command.

           
          Step 4end


          Example: 
          
Switch(config)# end
           

          Returns to privileged EXEC mode.

           
          Step 5show ip igmp snooping mrouter [vlan vlan-id]


          Example: 
          
Switch# show ip igmp snooping mrouter vlan 5
           

          Verifies that IGMP snooping is enabled on the VLAN interface.

           
          Step 6copy running-config startup-config


          Example: 
          Switch# copy running-config startup-config
           

          (Optional) Saves your entries in the configuration file.

           
          Related References
          Example: Enabling a Static Connection to a Multicast Router

          Configuring a Host Statically to Join a Group

          Hosts or Layer 2 ports normally join multicast groups dynamically, but you can also statically configure a host on an interface.

          Follow these steps to add a Layer 2 port as a member of a multicast group:

          SUMMARY STEPS

            1.    enable

            2.    configure terminal

            3.    ip igmp snooping vlan vlan-id static ip_address interface interface-id

            4.    end

            5.    show ip igmp snooping groups

            6.    copy running-config startup-config


          DETAILED STEPS
             Command or ActionPurpose
            Step 1 enable


            Example: 
            Switch> enable
             

            Enables privileged EXEC mode. Enter your password if prompted.

             

            Step 2configure terminal


            Example: 
            
Switch# configure terminal
             

            Enters the global configuration mode.

             
            Step 3ip igmp snooping vlan vlan-id static ip_address interface interface-id


            Example: 
            
Switch(config)# ip igmp snooping vlan 105 static 230.0.0.1 interface gigabitethernet1/0/1
             

            Statically configures a Layer 2 port as a member of a multicast group:

            • vlan-id is the multicast group VLAN ID. The range is 1 to 1001 and 1006 to 4094.

            • ip-address is the group IP address.

            • interface-id is the member port. It can be a physical interface or a port channel (1 to 128).

            Note   

            To remove the Layer 2 port from the multicast group, use the no ip igmp snooping vlan vlan-id static mac-address interface interface-id global configuration command.

             
            Step 4end


            Example: 
            
Switch(config)# end
             

            Returns to privileged EXEC mode.

             
            Step 5show ip igmp snooping groups


            Example: 
            
Switch# show ip igmp snooping groups
             

            Verifies the member port and the IP address.

             
            Step 6copy running-config startup-config


            Example: 
            Switch# copy running-config startup-config
             

            (Optional) Saves your entries in the configuration file.

             
            Related Concepts
            Joining a Multicast Group
            Related References
            Example: Statically Configuring a Host on a Port

            Enabling IGMP Immediate Leave

            When you enable IGMP Immediate Leave, the switch immediately removes a port when it detects an IGMP Version 2 leave message on that port. You should use the Immediate-Leave feature only when there is a single receiver present on every port in the VLAN.


            Note

            Immediate Leave is supported only on IGMP Version 2 hosts. IGMP Version 2 is the default version for the switch.

            SUMMARY STEPS

              1.    enable

              2.    configure terminal

              3.    ip igmp snooping vlan vlan-id immediate-leave

              4.    end

              5.    show ip igmp snooping vlan vlan-id

              6.    end


            DETAILED STEPS
               Command or ActionPurpose
              Step 1 enable


              Example: 
              Switch> enable
               

              Enables privileged EXEC mode. Enter your password if prompted.

               

              Step 2configure terminal


              Example: 
              
Switch# configure terminal
               

              Enters the global configuration mode.

               
              Step 3ip igmp snooping vlan vlan-id immediate-leave


              Example: 
              
Switch(config)# ip igmp snooping vlan 21 immediate-leave
               

              Enables IGMP Immediate Leave on the VLAN interface.

              Note   

              To disable IGMP Immediate Leave on a VLAN, use the no ip igmp snooping vlan vlan-id immediate-leave global configuration command.

               
              Step 4end


              Example: 
              
Switch(config)# end
               

              Returns to privileged EXEC mode.

               
              Step 5show ip igmp snooping vlan vlan-id


              Example: 
              
Switch# show ip igmp snooping vlan 21
               

              Verifies that Immediate Leave is enabled on the VLAN interface.

               
              Step 6end


              Example: 
              
Switch(config)# end
               

              Returns to privileged EXEC mode.

               
              Related Concepts
              Immediate Leave
              Related References
              Example: Enable Immediate Leave on a VLAN

              Configuring the IGMP Leave Timer

              You can configure the leave time globally or on a per-VLAN basis. Follow these steps to enable the IGMP configurable-leave timer:

              SUMMARY STEPS

                1.    enable

                2.    configure terminal

                3.    ip igmp snooping last-member-query-interval time

                4.    ip igmp snooping vlan vlan-id last-member-query-interval time

                5.    end

                6.    show ip igmp snooping

                7.    copy running-config startup-config


              DETAILED STEPS
                 Command or ActionPurpose
                Step 1 enable


                Example: 
                Switch> enable
                 

                Enables privileged EXEC mode. Enter your password if prompted.

                 

                Step 2configure terminal


                Example: 
                
Switch# configure terminal
                 

                Enters the global configuration mode.

                 
                Step 3ip igmp snooping last-member-query-interval time


                Example: 
                
Switch(config)# ip igmp snooping last-member-query-interval 1000
                 

                Configures the IGMP leave timer globally. The range is 100 to 32767 milliseconds.

                The default leave time is 1000 milliseconds.

                Note   

                To globally reset the IGMP leave timer to the default setting, use the no ip igmp snooping last-member-query-interval global configuration command.

                 
                Step 4ip igmp snooping vlan vlan-id last-member-query-interval time


                Example: 
                
Switch(config)# ip igmp snooping vlan 210 last-member-query-interval 1000
                 

                (Optional) Configures the IGMP leave time on the VLAN interface. The range is 100 to 32767 milliseconds.

                Note   

                Configuring the leave time on a VLAN overrides the globally configured timer.

                Note   

                To remove the configured IGMP leave-time setting from the specified VLAN, use the no ip igmp snooping vlan vlan-id last-member-query-interval global configuration command.

                 
                Step 5end


                Example: 
                
Switch(config)# end
                 

                Returns to privileged EXEC mode.

                 
                Step 6show ip igmp snooping


                Example: 
                
Switch# show ip igmp snooping
                 

                (Optional) Displays the configured IGMP leave time.

                 
                Step 7copy running-config startup-config


                Example: 
                Switch# copy running-config startup-config
                 

                (Optional) Saves your entries in the configuration file.

                 
                Related Concepts
                IGMP Configurable-Leave Timer

                Configuring TCN-Related Commands

                Controlling the Multicast Flooding Time After a TCN Event

                You can configure the number of general queries by which multicast data traffic is flooded after a topology change notification (TCN) event. If you set the TCN flood query count to 1 the flooding stops after receiving 1 general query. If you set the count to 7, the flooding continues until 7 general queries are received. Groups are relearned based on the general queries received during the TCN event.

                Some examples of TCN events are when the client location is changed and the receiver is on same port that was blocked but is now forwarding, and when a port goes down without sending a leave message.

                Follow these steps to configure the TCN flood query count:

                SUMMARY STEPS

                  1.    enable

                  2.    configure terminal

                  3.    ip igmp snooping tcn flood query count count

                  4.    end

                  5.    show ip igmp snooping

                  6.    copy running-config startup-config


                DETAILED STEPS
                   Command or ActionPurpose
                  Step 1 enable


                  Example: 
                  Switch> enable
                   

                  Enables privileged EXEC mode. Enter your password if prompted.

                   

                  Step 2configure terminal


                  Example: 
                  
Switch# configure terminal
                   

                  Enters the global configuration mode.

                   
                  Step 3ip igmp snooping tcn flood query count count


                  Example: 
                  
Switch(config)# ip igmp snooping tcn flood query count 3
                   

                  Specifies the number of IGMP general queries for which the multicast traffic is flooded.

                  The range is 1 to 10. The default, the flooding query count is 2.

                  Note   

                  To return to the default flooding query count, use the no ip igmp snooping tcn flood query count global configuration command.

                   
                  Step 4end


                  Example: 
                  
Switch(config)# end
                   

                  Returns to privileged EXEC mode.

                   
                  Step 5show ip igmp snooping


                  Example: 
                  
Switch# show ip igmp snooping
                   

                  Verifies the TCN settings.

                   
                  Step 6copy running-config startup-config


                  Example: 
                  Switch# copy running-config startup-config
                   

                  (Optional) Saves your entries in the configuration file.

                   

                  Recovering from Flood Mode

                  When a topology change occurs, the spanning-tree root sends a special IGMP leave message (also known as global leave) with the group multicast address 0.0.0.0. However, you can enable the switch to send the global leave message whether it is the spanning-tree root or not. When the router receives this special leave, it immediately sends general queries, which expedite the process of recovering from the flood mode during the TCN event. Leaves are always sent if the switch is the spanning-tree root regardless of this configuration.

                  Follow these steps to enable sending of leave messages:

                  SUMMARY STEPS

                    1.    enable

                    2.    configure terminal

                    3.    ip igmp snooping tcn query solicit

                    4.    end

                    5.    show ip igmp snooping

                    6.    copy running-config startup-config


                  DETAILED STEPS
                     Command or ActionPurpose
                    Step 1 enable


                    Example: 
                    Switch> enable
                     

                    Enables privileged EXEC mode. Enter your password if prompted.

                     

                    Step 2configure terminal


                    Example: 
                    
Switch# configure terminal
                     

                    Enters the global configuration mode.

                     
                    Step 3ip igmp snooping tcn query solicit


                    Example: 
                    
Switch(config)# ip igmp snooping tcn query solicit
                     

                    Sends an IGMP leave message (global leave) to speed the process of recovering from the flood mode caused during a TCN event. By default, query solicitation is disabled.

                    Note   

                    To return to the default query solicitation, use the no ip igmp snooping tcn query solicit global configuration command.

                     
                    Step 4end


                    Example: 
                    
Switch(config)# end
                     

                    Returns to privileged EXEC mode.

                     
                    Step 5show ip igmp snooping


                    Example: 
                    
Switch# show ip igmp snooping
                     

                    Verifies the TCN settings.

                     
                    Step 6copy running-config startup-config


                    Example: 
                    Switch# copy running-config startup-config
                     

                    (Optional) Saves your entries in the configuration file.

                     

                    Disabling Multicast Flooding During a TCN Event

                    When the switch receives a TCN, multicast traffic is flooded to all the ports until 2 general queries are received. If the switch has many ports with attached hosts that are subscribed to different multicast groups, this flooding might exceed the capacity of the link and cause packet loss. Follow these steps to control TCN flooding:

                    SUMMARY STEPS

                      1.    enable

                      2.    configure terminal

                      3.    interface interface-id

                      4.    no ip igmp snooping tcn flood

                      5.    end

                      6.    show ip igmp snooping

                      7.    copy running-config startup-config


                    DETAILED STEPS
                       Command or ActionPurpose
                      Step 1 enable


                      Example: 
                      Switch> enable
                       

                      Enables privileged EXEC mode. Enter your password if prompted.

                       

                      Step 2configure terminal


                      Example: 
                      
Switch# configure terminal
                       

                      Enters the global configuration mode.

                       
                      Step 3interface interface-id


                      Example: 
                      
Switch(config)# interface gigabitethernet 1/0/1
                       

                      Specifies the interface to be configured, and enters interface configuration mode.

                       
                      Step 4no ip igmp snooping tcn flood


                      Example: 
                      
Switch(config-if)# no ip igmp snooping tcn flood
                       

                      Disables the flooding of multicast traffic during a spanning-tree TCN event.

                      By default, multicast flooding is enabled on an interface.

                      Note   

                      To re-enable multicast flooding on an interface, use the ip igmp snooping tcn flood interface configuration command.

                       
                      Step 5end


                      Example: 
                      
Switch(config)# end
                       

                      Returns to privileged EXEC mode.

                       
                      Step 6show ip igmp snooping


                      Example: 
                      
Switch# show ip igmp snooping
                       

                      Verifies the TCN settings.

                       
                      Step 7copy running-config startup-config


                      Example: 
                      Switch# copy running-config startup-config
                       

                      (Optional) Saves your entries in the configuration file.

                       

                      Configuring the IGMP Snooping Querier

                      Follow these steps to enable the IGMP snooping querier feature in a VLAN:

                      SUMMARY STEPS

                        1.    enable

                        2.    configure terminal

                        3.    ip igmp snooping querier

                        4.    ip igmp snooping querier address ip_address

                        5.    ip igmp snooping querier query-interval interval-count

                        6.    ip igmp snooping querier tcn query [count count | interval interval]

                        7.    ip igmp snooping querier timer expiry timeout

                        8.    ip igmp snooping querier version version

                        9.    end

                        10.    show ip igmp snooping vlan vlan-id

                        11.    copy running-config startup-config


                      DETAILED STEPS
                         Command or ActionPurpose
                        Step 1 enable


                        Example: 
                        Switch> enable
                         

                        Enables privileged EXEC mode. Enter your password if prompted.

                         

                        Step 2configure terminal


                        Example: 
                        
Switch# configure terminal
                         

                        Enters the global configuration mode.

                         
                        Step 3ip igmp snooping querier


                        Example: 
                        
Switch(config)# ip igmp snooping querier
                         

                        Enables the IGMP snooping querier.

                         
                        Step 4ip igmp snooping querier address ip_address


                        Example: 
                        
Switch(config)# ip igmp snooping querier address 172.16.24.1
                         

                        (Optional) Specifies an IP address for the IGMP snooping querier. If you do not specify an IP address, the querier tries to use the global IP address configured for the IGMP querier.

                        Note   

                        The IGMP snooping querier does not generate an IGMP general query if it cannot find an IP address on the switch.

                         
                        Step 5ip igmp snooping querier query-interval interval-count


                        Example: 
                        
Switch(config)# ip igmp snooping querier query-interval 30
                         

                        (Optional) Sets the interval between IGMP queriers. The range is 1 to 18000 seconds.

                         
                        Step 6ip igmp snooping querier tcn query [count count | interval interval]


                        Example: 
                        
Switch(config)# ip igmp snooping querier tcn query interval 20
                         

                        (Optional) Sets the time between Topology Change Notification (TCN) queries. The count range is 1 to 10. The interval range is 1 to 255 seconds.

                         
                        Step 7ip igmp snooping querier timer expiry timeout


                        Example: 
                        
Switch(config)# ip igmp snooping querier timer expiry 180
                         

                        (Optional) Sets the length of time until the IGMP querier expires. The range is 60 to 300 seconds.

                         
                        Step 8ip igmp snooping querier version version


                        Example: 
                        
Switch(config)# ip igmp snooping querier version 2
                         

                        (Optional) Selects the IGMP version number that the querier feature uses. Select 1 or 2.

                         
                        Step 9end


                        Example: 
                        
Switch(config)# end
                         

                        Returns to privileged EXEC mode.

                         
                        Step 10show ip igmp snooping vlan vlan-id


                        Example: 
                        
Switch# show ip igmp snooping vlan 30
                         

                        (Optional) Verifies that the IGMP snooping querier is enabled on the VLAN interface. The VLAN ID range is 1 to 1001 and 1006 to 4094.

                         
                        Step 11copy running-config startup-config


                        Example: 
                        Switch# copy running-config startup-config
                         

                        (Optional) Saves your entries in the configuration file.

                         
                        Related Concepts
                        IGMP Snooping and Switch Stacks
                        Related References
                        Example: Setting the IGMP Snooping Querier Source Address
                        Example: Setting the IGMP Snooping Querier Maximum Response Time
                        Example: Setting the IGMP Snooping Querier Timeout
                        Example: Setting the IGMP Snooping Querier Feature

                        Disabling IGMP Report Suppression

                        Follow these steps to disable IGMP report suppression:

                        SUMMARY STEPS

                          1.    enable

                          2.    configure terminal

                          3.    no ip igmp snooping report-suppression

                          4.    end

                          5.    show ip igmp snooping

                          6.    copy running-config startup-config


                        DETAILED STEPS
                           Command or ActionPurpose
                          Step 1 enable


                          Example: 
                          Switch> enable
                           

                          Enables privileged EXEC mode. Enter your password if prompted.

                           

                          Step 2configure terminal


                          Example: 
                          
Switch# configure terminal
                           

                          Enters the global configuration mode.

                           
                          Step 3no ip igmp snooping report-suppression


                          Example: 
                          
Switch(config)# no ip igmp snooping report-suppression
                           

                          Disables IGMP report suppression. When report suppression is disabled, all IGMP reports are forwarded to the multicast routers.

                          IGMP report suppression is enabled by default.

                          When IGMP report supression is enabled, the switch forwards only one IGMP report per multicast router query.
                          Note   

                          To re-enable IGMP report suppression, use the ip igmp snooping report-suppression global configuration command.

                           
                          Step 4end


                          Example: 
                          
Switch(config)# end
                           

                          Returns to privileged EXEC mode.

                           
                          Step 5show ip igmp snooping


                          Example: 
                          
Switch# show ip igmp snooping
                           

                          Verifies that IGMP report suppression is disabled.

                           
                          Step 6copy running-config startup-config


                          Example: 
                          Switch# copy running-config startup-config
                           

                          (Optional) Saves your entries in the configuration file.

                           
                          Related Concepts
                          IGMP Report Suppression

                          Configuring IGMP Profiles

                          Follow these steps to create an IGMP profile:

                          This task is optional.

                          SUMMARY STEPS

                            1.    enable

                            2.    configure terminal

                            3.    ip igmp profile profile number

                            4.    permit | deny

                            5.    range ip multicast address

                            6.    end

                            7.    show ip igmp profile profile number

                            8.    show running-config

                            9.    copy running-config startup-config


                          DETAILED STEPS
                             Command or ActionPurpose
                            Step 1 enable


                            Example: 
                            Switch> enable
                             

                            Enables privileged EXEC mode. Enter your password if prompted.

                             

                            Step 2configure terminal


                            Example: 
                            
Switch# configure terminal
                             

                            Enters the global configuration mode.

                             
                            Step 3ip igmp profile profile number


                            Example: 
                            
Switch(config)# ip igmp profile 3
                             
                            Assigns a number to the profile you are configuring, and enters IGMP profile configuration mode. The profile number range is 1 to 4294967295. When you are in IGMP profile configuration mode, you can create the profile by using these commands:

                            • deny—Specifies that matching addresses are denied; this is the default.

                            • exit—Exits from igmp-profile configuration mode.

                            • no—Negates a command or returns to its defaults.

                            • permit—Specifies that matching addresses are permitted.

                            • range—Specifies a range of IP addresses for the profile. You can enter a single IP address or a range with a start and an end address.

                            The default is for the switch to have no IGMP profiles configured.

                            Note    To delete a profile, use the no ip igmp profile profile number global configuration command.
                             
                            Step 4permit | deny

                            Example: 
                            
Switch(config-igmp-profile)# permit
                             

                            (Optional) Sets the action to permit or deny access to the IP multicast address. If no action is configured, the default for the profile is to deny access.

                             
                            Step 5range ip multicast address


                            Example: 
                            
Switch(config-igmp-profile)# range 229.9.9.0
                             

                            Enters the IP multicast address or range of IP multicast addresses to which access is being controlled. If entering a range, enter the low IP multicast address, a space, and the high IP multicast address.

                            You can use the range command multiple times to enter multiple addresses or ranges of addresses.

                            Note   

                            To delete an IP multicast address or range of IP multicast addresses, use the no range ip multicast address IGMP profile configuration command.

                             
                            Step 6end


                            Example: 
                            
Switch(config)# end
                             

                            Returns to privileged EXEC mode.

                             
                            Step 7show ip igmp profile profile number


                            Example: 
                            
Switch# show ip igmp profile 3
                             

                            Verifies the profile configuration.

                             
                            Step 8show running-config


                            Example: 
                            
Switch# show running-config
                             

                            Verifies your entries.

                             
                            Step 9copy running-config startup-config


                            Example: 
                            Switch# copy running-config startup-config
                             

                            (Optional) Saves your entries in the configuration file.

                             
                            Related References
                            Example: Configuring IGMP Profiles

                            Applying IGMP Profiles

                            To control access as defined in an IGMP profile, you have to apply the profile to the appropriate interfaces. You can apply IGMP profiles only to Layer 2 access ports; you cannot apply IGMP profiles to routed ports or SVIs. You cannot apply profiles to ports that belong to an EtherChannel port group. You can apply a profile to multiple interfaces, but each interface can have only one profile applied to it.

                            Follow these steps to apply an IGMP profile to a switch port:

                            SUMMARY STEPS

                              1.    enable

                              2.    configure terminal

                              3.    interface interface-id

                              4.    ip igmp filter profile number

                              5.    end

                              6.    show running-config

                              7.    copy running-config startup-config


                            DETAILED STEPS
                               Command or ActionPurpose
                              Step 1 enable


                              Example: 
                              Switch> enable
                               

                              Enables privileged EXEC mode. Enter your password if prompted.

                               

                              Step 2configure terminal


                              Example: 
                              
Switch# configure terminal
                               

                              Enters the global configuration mode.

                               
                              Step 3interface interface-id


                              Example: 
                              
Switch(config)# interface gigabitethernet1/0/1
                               

                              Specifies the physical interface, and enters interface configuration mode. The interface must be a Layer 2 port that does not belong to an EtherChannel port group.

                               
                              Step 4ip igmp filter profile number


                              Example: 
                              
Switch(config-if)# ip igmp filter 321
                               

                              Applies the specified IGMP profile to the interface. The range is 1 to 4294967295.

                              Note   

                              To remove a profile from an interface, use the no ip igmp filter profile number interface configuration command.

                               
                              Step 5end


                              Example: 
                              
Switch(config-if)# end
                               

                              Returns to privileged EXEC mode.

                               
                              Step 6show running-config


                              Example: 
                              
Switch# show running-config
                               

                              Verifies your entries.

                               
                              Step 7copy running-config startup-config


                              Example: 
                              Switch# copy running-config startup-config
                               

                              (Optional) Saves your entries in the configuration file.

                               
                              Related References
                              Example: Applying IGMP Profile

                              Setting the Maximum Number of IGMP Groups

                              You can set the maximum number of IGMP groups that a Layer 2 interface can join by using the ip igmp max-groups interface configuration command.

                              Use the no form of this command to set the maximum back to the default, which 208.

                              This restriction can be applied to Layer 2 ports only; you cannot set a maximum number of IGMP groups on routed ports or SVIs. You also can use this command on a logical EtherChannel interface but cannot use it on ports that belong to an EtherChannel port group.

                              SUMMARY STEPS

                                1.    configure terminal

                                2.    interface interface-id

                                3.    ip igmp max-groups number

                                4.    end

                                5.    show running-config interface interface-id

                                6.    copy running-config startup-config


                              DETAILED STEPS
                                 Command or ActionPurpose
                                Step 1configure terminal


                                Example: 
                                
Switch# configure terminal
                                 

                                Enters the global configuration mode.

                                 
                                Step 2interface interface-id


                                Example:
                                
Switch(config)# interface gigabitethernet1/0/2
                                 

                                Specifies the interface to be configured, and enters interface configuration mode. The interface can be a Layer 2 port that does not belong to an EtherChannel group or a EtherChannel interface.

                                 
                                Step 3ip igmp max-groups number


                                Example:
                                
Switch(config-if)# ip igmp max-groups 20
                                 

                                Sets the maximum number of IGMP groups that the interface can join. The range is 0 to 4294967294. The default is 208.

                                Note   

                                To remove the maximum group limitation and return to the default of no maximum, use the no ip igmp max-groups interface configuration command.

                                 
                                Step 4end


                                Example:
                                
Switch(config-if)# end
                                 

                                Returns to privileged EXEC mode.

                                 
                                Step 5show running-config interface interface-id


                                Example:
                                
Switch# show running-config interface gigabitethernet1/0/1
                                 

                                Verifies your entries.

                                 
                                Step 6copy running-config startup-config


                                Example:
                                
Switch# copy running-config startup-config
                                 

                                (Optional) Saves your entries in the configuration file.

                                 

                                Configuring the IGMP Throttling Action

                                After you set the maximum number of IGMP groups that a Layer 2 interface can join, you can configure an interface to replace the existing group with the new group for which the IGMP report was received.

                                Follow these steps to configure the throttling action when the maximum number of entries is in the forwarding table:

                                SUMMARY STEPS

                                  1.    enable

                                  2.    configure terminal

                                  3.    interface interface-id

                                  4.    ip igmp max-groups action {deny | replace}

                                  5.    end

                                  6.    show running-config interface interface-id

                                  7.    copy running-config startup-config


                                DETAILED STEPS
                                   Command or ActionPurpose
                                  Step 1 enable


                                  Example: 
                                  Switch> enable
                                   

                                  Enables privileged EXEC mode. Enter your password if prompted.

                                   

                                  Step 2configure terminal


                                  Example: 
                                  
Switch# configure terminal
                                   

                                  Enters the global configuration mode.

                                   
                                  Step 3interface interface-id


                                  Example: 
                                  
Switch(config)# interface gigabitethernet 1/0/1
                                   

                                  Specifies the physical interface to be configured, and enters interface configuration mode. The interface can be a Layer 2 port that does not belong to an EtherChannel group or an EtherChannel interface. The interface cannot be a trunk port.

                                   
                                  Step 4ip igmp max-groups action {deny | replace}


                                  Example: 
                                  
Switch(config-if)# ip igmp max-groups action replace
                                   

                                  When an interface receives an IGMP report and the maximum number of entries is in the forwarding table, specifies the action that the interface takes:

                                  • deny—Drops the report. If you configure this throttling action, the entries that were previously in the forwarding table are not removed but are aged out. After these entries are aged out and the maximum number of entries is in the forwarding table, the switch drops the next IGMP report received on the interface.

                                  • replace—Replaces the existing group with the new group for which the IGMP report was received. If you configure this throttling action, the entries that were previously in the forwarding table are removed. When the maximum number of entries is in the forwarding table, the switch replaces a randomly selected entry with the received IGMP report.

                                  To prevent the switch from removing the forwarding-table entries, you can configure the IGMP throttling action before an interface adds entries to the forwarding table.

                                  Note   

                                  To return to the default action of dropping the report, use the no ip igmp max-groups action interface configuration command.

                                   
                                  Step 5end


                                  Example: 
                                  
Switch(config)# end
                                   

                                  Returns to privileged EXEC mode.

                                   
                                  Step 6show running-config interface interface-id


                                  Example: 
                                  
Switch# show running-config interface gigabitethernet1/0/1
                                   

                                  Verifies your entries.

                                   
                                  Step 7copy running-config startup-config


                                  Example: 
                                  Switch# copy running-config startup-config
                                   

                                  (Optional) Saves your entries in the configuration file.

                                   
                                  Related Concepts
                                  IGMP Filtering and Throttling

                                  Monitoring IGMP Snooping

                                  Monitoring IGMP Snooping Information

                                  You can display IGMP snooping information for dynamically learned and statically configured router ports and VLAN interfaces. You can also display MAC address multicast entries for a VLAN configured for IGMP snooping.

                                  Table 5 Commands for Displaying IGMP Snooping Information

                                  Command

                                  Purpose

                                  show ip igmp snooping [vlan vlan-id [detail] ]

                                  Displays the snooping configuration information for all VLANs on the switch or for a specified VLAN.

                                  (Optional) Enter vlan vlan-id to display information for a single VLAN. The VLAN ID range is 1 to 1001 and 1006 to 4094.

                                  show ip igmp snooping groups [count |dynamic [count] | user [count]]

                                  Displays multicast table information for the switch or about a specific parameter:

                                  • count—Displays the total number of entries for the specified command options instead of the actual entries.

                                  • dynamic—Displays entries learned through IGMP snooping.

                                  • user—Displays only the user-configured multicast entries.

                                  show ip igmp snooping groups vlan vlan-id 
[ip_address | count | dynamic [count] | user[count]]

                                  Displays multicast table information for a multicast VLAN or about a specific parameter for the VLAN:

                                  • vlan-id—The VLAN ID range is 1 to 1001 and 1006 to 4094.

                                  • count—Displays the total number of entries for the specified command options instead of the actual entries.

                                  • dynamic—Displays entries learned through IGMP snooping.

                                  • ip_address—Displays characteristics of the multicast group with the specified group IP address.

                                  • user—Displays only the user-configured multicast entries.

                                  show ip igmp snooping mrouter [vlan vlan-id]

                                  Displays information on dynamically learned and manually configured multicast router interfaces.

                                  Note   

                                  When you enable IGMP snooping, the switch automatically learns the interface to which a multicast router is connected. These are dynamically learned interfaces.

                                  (Optional) Enter the vlan vlan-id to display information for a particular VLAN.

                                  show ip igmp snooping querier [vlan vlan-id] detail

                                  Displays information about the IP address and receiving port of the most-recently received IGMP query message in the VLAN and the configuration and operational state of the IGMP snooping querier in the VLAN.

                                  Monitoring IGMP Filtering and Throttling Configuration

                                  You can display IGMP profile characteristics, and you can display the IGMP profile and maximum group configuration for all interfaces on the switch or for a specified interface. You can also display the IGMP throttling configuration for all interfaces on the switch or for a specified interface.

                                  Table 6 Commands for Displaying IGMP Filtering and Throttling Configuration

                                  Command

                                  Purpose

                                  show ip igmp profile [profile number]

                                  Displays the specified IGMP profile or all the IGMP profiles defined on the switch.

                                  show running-config [interface interface-id]

                                  Displays the configuration of the specified interface or the configuration of all interfaces on the switch, including (if configured) the maximum number of IGMP groups to which an interface can belong and the IGMP profile applied to the interface.

                                  Configuration Examples for IGMP Snooping

                                  Example: Configuring IGMP Snooping Using CGMP Packets

                                  This example shows how to configure IGMP snooping to use CGMP packets as the learning method: 
                                  Switch# configure terminal
Switch(config)# ip igmp snooping vlan 1 mrouter learn cgmp
Switch(config)# end
                                  Related Tasks
                                  Setting the Snooping Method

                                  Example: Enabling a Static Connection to a Multicast Router

                                  This example shows how to enable a static connection to a multicast router:

                                  
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 200 mrouter interface gigabitethernet1/0/2
Switch(config)# end
                                  Related Tasks
                                  Configuring a Multicast Router Port

                                  Example: Statically Configuring a Host on a Port

                                  This example shows how to statically configure a host on a port:

                                  
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 105 static 224.2.4.12 interface gigabitethernet1/0/1
Switch(config)# end
                                  Related Concepts
                                  Joining a Multicast Group
                                  Related Tasks
                                  Configuring a Host Statically to Join a Group

                                  Example: Enable Immediate Leave on a VLAN

                                  This example shows how to enable IGMP Immediate Leave on VLAN 130:

                                  
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 130 immediate-leave
Switch(config)# end
                                  Related Concepts
                                  Immediate Leave
                                  Related Tasks
                                  Enabling IGMP Immediate Leave

                                  Example: Setting the IGMP Snooping Querier Source Address

                                  This example shows how to set the IGMP snooping querier source address to 10.0.0.64:

                                  
Switch# configure terminal
Switch(config)# ip igmp snooping querier 10.0.0.64
Switch(config)# end
                                  Related Concepts
                                  IGMP Snooping and Switch Stacks
                                  Related Tasks
                                  Configuring the IGMP Snooping Querier

                                  Example: Setting the IGMP Snooping Querier Maximum Response Time

                                  This example shows how to set the IGMP snooping querier maximum response time to 25 seconds:

                                  
Switch# configure terminal
Switch(config)# ip igmp snooping querier query-interval 25
Switch(config)# end
                                  Related Concepts
                                  IGMP Snooping and Switch Stacks
                                  Related Tasks
                                  Configuring the IGMP Snooping Querier

                                  Example: Setting the IGMP Snooping Querier Timeout

                                  This example shows how to set the IGMP snooping querier timeout to 60 seconds:

                                  
Switch# configure terminal
Switch(config)# ip igmp snooping querier timeout expiry 60
Switch(config)# end
                                  Related Concepts
                                  IGMP Snooping and Switch Stacks
                                  Related Tasks
                                  Configuring the IGMP Snooping Querier

                                  Example: Setting the IGMP Snooping Querier Feature

                                  This example shows how to set the IGMP snooping querier feature to Version 2:

                                  
Switch# configure terminal
Switch(config)# ip igmp snooping querier version 2
Switch(config)# end
                                  Related Concepts
                                  IGMP Snooping and Switch Stacks
                                  Related Tasks
                                  Configuring the IGMP Snooping Querier

                                  Example: Configuring IGMP Profiles

                                  This example shows how to create IGMP profile 4 allowing access to the single IP multicast address and how to verify the configuration. If the action was to deny (the default), it would not appear in the show ip igmp profile output display. 
                                  Switch(config)# ip igmp profile 4
Switch(config-igmp-profile)# permit
Switch(config-igmp-profile)# range 229.9.9.0
Switch(config-igmp-profile)# end
Switch# show ip igmp profile 4
IGMP Profile 4
    permit
    range 229.9.9.0 229.9.9.0
                                  Related Tasks
                                  Configuring IGMP Profiles

                                  Example: Applying IGMP Profile

                                  This example shows how to apply IGMP profile 4 to a port: 
                                  Switch(config)# interface gigabitethernet1/0/2
Switch(config-if)# ip igmp filter 4
Switch(config-if)# end
                                  Related Tasks
                                  Applying IGMP Profiles

                                  Example: Setting the Maximum Number of IGMP Groups

                                  This example shows how to limit to 25 the number of IGMP groups that a port can join: 
                                  Switch(config)# interface gigabitethernet1/0/2
Switch(config-if)# ip igmp max-groups 25
Switch(config-if)# end
                                  Related Tasks
                                  Setting the Maximum Number of IGMP Groups

                                  Where to Go Next for IGMP Snooping

                                  You can configure the following:

                                  • Multicast VLAN Registration

                                  Additional References

                                  Related Documents

                                  Related Topic Document Title

                                  For complete syntax and usage information for the commands used in this chapter.

                                  Catalyst 2960-X Switch IGMP Snooping Command Reference

                                  Standards and RFCs

                                  Standard/RFC Title

                                  RFC 1112

                                  Host Extensions for IP Multicasting

                                  RFC 2236

                                  Internet Group Management Protocol, Version 2

                                  MIBs

                                  MIB MIBs Link

                                  All supported MIBs for this release.

                                  To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

                                  http:/​/​www.cisco.com/​go/​mibs

                                  Technical Assistance

                                  Description Link

                                  The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

                                  To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

                                  Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

                                  http:/​/​www.cisco.com/​support

                                  Feature History and Information for IGMP Snooping

                                  Release Modification

                                  Cisco IOS 15.0(2)EX

                                  This feature was introduced.