Catalyst 6500 Release 12.2SX Software Configuration Guide

Configuring MVR for IPv4 Multicast Traffic

This chapter describes how to configure Multicast VLAN Registration (MVR) for IPv4 multicast traffic in Cisco IOS Release 12.2SX.

Note•For complete syntax and usage information for the commands used in this chapter, see the Cisco IOS Master Command List, at this URL:

http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.html

•To constrain IPv6 Multicast traffic, see Chapter 36 "Configuring MLD Snooping for IPv6 Multicast Traffic."

Tip For additional information about Cisco Catalyst 6500 Series Switches (including configuration examples and troubleshooting information), see the documents listed on this page:

http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.html

Participate in the Technical Documentation Ideas forum

This chapter consists of these sections:

•Understanding MVR

•Configuring MVR

•Displaying MVR Information

Understanding MVR

Release 12.2(33)SXH and later releases support Multicast VLAN Registration (MVR). MVR is designed for applications that use wide-scale deployment of multicast traffic across an Ethernet ring-based service-provider network (for example, the broadcast of multiple television channels over a service-provider network). MVR allows a subscriber on a port to subscribe and unsubscribe to a multicast stream on the network-wide multicast VLAN. It allows the single multicast VLAN to be shared in the network while subscribers remain in separate VLANs. MVR provides the ability to continuously send multicast streams in the multicast VLAN, but to isolate the streams from the subscriber VLANs for bandwidth and security reasons.

MVR assumes that subscriber ports subscribe and unsubscribe (join and leave) these multicast streams by sending out IGMP join and leave messages. These messages can originate from an IGMP Version-2-compatible host with an Ethernet connection. Although MVR operates on the underlying mechanism of IGMP snooping, the two features operate independently of each other. One feature can be enabled or disabled without affecting the operation of the other feature. However, if IGMP snooping and MVR are both enabled, MVR reacts only to join and leave messages from multicast groups configured under MVR. Join and leave messages from all other multicast groups are managed by IGMP snooping.

MVR does the following:

•Identifies the MVR IP multicast streams and their associated IP multicast group in the Layer 2 forwarding table.

•Intercepts the IGMP messages.

•Modifies the Layer 2 forwarding table to include or remove the subscriber as a receiver of the multicast stream, even though the receivers might be in a different VLAN from the source.

This forwarding behavior selectively allows traffic to cross between different VLANs.

The switch will forward multicast data for MVR IP multicast streams only to MVR ports on which hosts have joined, either by IGMP reports or by MVR static configuration. The switch will forward IGMP reports received from MVR hosts only to the source (uplink) port. This eliminates using unnecessary bandwidth on MVR data port links.

Only Layer 2 ports participate in MVR. You must configure ports as MVR receiver ports. Only one MVR multicast VLAN per switch.

Using MVR in a Multicast Television Application

In a multicast television application, a PC or a television with a set-top box can receive the multicast stream. Multiple set-top boxes or PCs can be connected to one subscriber port, which is a switch port configured as an MVR receiver port. Figure 39-1 is an example configuration. DHCP assigns an IP address to the set-top box or the PC. When a subscriber selects a channel, the set-top box or PC sends an IGMP report to Switch A to join the appropriate multicast. If the IGMP report matches one of the configured IP multicast group addresses, the SP CPU modifies the hardware address table to include this receiver port and VLAN as a forwarding destination of the specified multicast stream when it is received from the multicast VLAN. Uplink ports that send and receive multicast data to and from the multicast VLAN are called MVR source ports.

Figure 39-1 Multicast VLAN Registration Example

When a subscriber changes channels or turns off the television, the set-top box sends an IGMP leave message for the multicast stream. The SP CPU sends a MAC-based general query through the receiver port VLAN. If there is another set-top box in the VLAN still subscribing to this group, that set-top box must respond within the maximum response time specified in the query. If the CPU does not receive a response, it eliminates the receiver port as a forwarding destination for this group.

Unless the Immediate Leave feature is enabled, when the switch receives an IGMP leave message from a subscriber on a receiver port, it sends out an IGMP query on that port and waits for IGMP group membership reports. If no reports are received in a configured time period, the receiver port is removed from multicast group membership. With the Immediate Leave feature enabled, an IGMP query is not sent from the receiver port on which the IGMP leave was received. As soon as the leave message is received, the receiver port is removed from multicast group membership, which speeds up leave latency. Enable the Immediate Leave feature only on receiver ports to which a single receiver device is connected.

MVR eliminates the need to duplicate television-channel multicast traffic for subscribers in each VLAN. Multicast traffic for all channels is only sent around the VLAN trunk once—only on the multicast VLAN. The IGMP leave and join messages are in the VLAN to which the subscriber port is assigned. These messages dynamically register for streams of multicast traffic in the multicast VLAN on the Layer 3 device, Switch B. The access layer switch, Switch A, modifies the forwarding behavior to allow the traffic to be forwarded from the multicast VLAN to the subscriber port in a different VLAN, selectively allowing traffic to cross between two VLANs.

IGMP reports are sent to the same IP multicast group address as the multicast data. The Switch A CPU must capture all IGMP join and leave messages from receiver ports and forward them to the multicast VLAN of the source (uplink) port.

Configuring MVR

These sections contain this configuration information:

•Default MVR Configuration

•MVR Configuration Guidelines and Limitations

•Configuring MVR Global Parameters

•Configuring MVR Interfaces

•Displaying MVR Information

•Clearing MVR Counters

Default MVR Configuration

Table 39-1 shows the default MVR configuration.

MVR Configuration Guidelines and Limitations

When configuring MVR, follow these guidelines:

•Only one MVR VLAN can be present in a switch, and you should configure the same VLAN as the MVR VLAN for all the switches in the same network.

•Source ports must be in the MVR VLAN.

•Receiver ports on a switch can be in different VLANs, but must not be in the MVR VLAN.

•Receiver ports can only be access ports; they cannot be trunk ports.

•When using private VLANs, you cannot configure a secondary VLAN as the MVR VLAN.

•Do not connect a multicast router to a receiver port.

•The MVR VLAN must not be a reverse path forwarding (RPF) interface for any multicast route.

•MVR data received on an MVR receiver port is not forwarded to MVR source ports.

•The maximum number of multicast entries (MVR group addresses) that can be configured on a switch (that is, the maximum number of television channels that can be received) is 8000.

•MVR is available only on native systems.

•VTP pruning should be disabled if the MVR VLAN number is between 1 and 1000.

•MVR can coexist with IGMP snooping on a switch.

•MVR supports IGMPv3 messages.

Configuring MVR Global Parameters

You do not need to set the optional MVR parameters if you choose to use the default settings. Before changing the default parameters (except for the MVR VLAN), you must first enable MVR.

Note For complete syntax and usage information for the commands used in this section, see the Cisco IOS Master Command List.

To configure the MVR global parameters, perform this task:

To return the switch to its default settings, use the no mvr [group ip-address | querytime | vlan] global configuration command.

This example shows how to enable MVR, configure the group address, set the query time to 1 second (10 tenths), and specify the MVR multicast VLAN as VLAN 22:

Router(config)# mvr

Router(config)# mvr group 228.1.23.4

Router(config)# mvr querytime 10

Router(config)# mvr vlan 22 

Router(config)# end 

You can use the show mvr groups privileged EXEC command to verify the MVR multicast group addresses on the switch.

Configuring MVR Interfaces

To configure Layer 2 MVR interfaces, perform this task:

To return the interface to its default settings, use the no mvr [type | immediate] interface configuration commands.

This example shows how to configure a source port and a receiver port and to configure Immediate Leave on the receiver port:

Router(config)# mvr

Router(config)# interface gigabitethernet 3/48

Router(config-if)# switchport

Router(config-if)# switchport access vlan 22

Router(config-if)# mvr type source 

Router(config-if)# exit

Router(config)# interface gigabitethernet 3/47

Router(config-if)# switchport

Router(config-if)# switchport access vlan 30

Router(config-if)# mvr type receiver 

Router(config-if)# mvr immediate

Router(config-if)# exit

Router(config)# 

Displaying MVR Information

You can display MVR information for the switch or for a specified interface. To display MVR configurations, perform one or more of these tasks:

This example displays MVR status and values for the switch:

Router# show mvr 

MVR Running: TRUE 

MVR multicast vlan: 22 

MVR Max Multicast Groups: 1000  

MVR Current multicast groups: 256  

MVR Global query response time: 10 (tenths of sec) 

This example displays the MVR group configuration:

Router# show mvr groups

MVR max Multicast Groups allowed: 8000 

MVR current multicast groups: 8000 

MVR groups: 

        Group start     Group end       Type  Count/Mask

        --------------- --------------- ----- ---------------

        225.0.7.226     225.0.7.226     count 1

        225.0.7.227     225.0.7.227     count 1

        225.0.7.228     225.0.7.228     count 1

        225.0.7.229     225.0.7.229     count 1

        225.0.7.230     225.0.7.230     count 1

        225.0.7.231     225.0.7.231     count 1

        236.8.7.0       236.8.7.255     mask  255.255.255.0  

        237.8.7.0       237.8.7.255     mask  255.255.255.0  

        237.8.8.0       237.8.8.255     mask  255.255.255.0  

This example displays all MVR interfaces and their MVR configurations:

Router# show mvr interface

Port      VLAN  Type       Status           Immediate Leave

----      ----  ----       ------           ---------------

Gi1/20       2  RECEIVER   ACTIVE/UP        DISABLED  

Gi1/21       2  SOURCE     ACTIVE/UP        DISABLED  

This example displays all MVR members on VLAN 2:

Router# show mvr members vlan 2

MVR Group IP      Status     Members

------------      ------     -------

224.000.001.001   ACTIVE     Gi1/20(u),Gi1/21(u)

224.000.001.002   ACTIVE     Fa3/2(d),Gi1/12(u)

This example displays the number of MVR members on all MVR VLANs:

Router# show mvr members count

Count of active MVR groups:

	Vlan 490: 400

	Vlan 600: 400

	Vlan 700: 0

	Vlan 950: 0

This example displays all receiver ports that are members of any IP multicast group:

Router# show mvr receiver-ports

Joins: v1,v2,v3 counter shows total IGMP joins

       v3 counter shows IGMP joins received with both MVR and non-MVR groups

Port   VLAN Status          Immediate            Joins

                              Leave         (v1,v2,v3)     (v3)

----   ---- -------------  ----------   ---------- -----------

Gi1/7   202 INACTIVE/UP    ENABLED           305336             0

Gi1/8   202 ACTIVE/UP     DISABLED             4005             0

Gi1/9   203 INACTIVE/DOWN DISABLED           53007            0

Gi1/10  203 ACTIVE/UP      DISABLED             6204             0

Gi1/11  204 ACTIVE/UP      DISABLED                0           940

Gi1/12  205 INACTIVE/UP    ENABLED              8623             0

Clearing MVR Counters

You can clear MVR join counters for the switch, for source or receiver ports, or for a specified interface.

To clear MVR counters, perform this task:

This example clears the join counters for the receiver port on GigabitEthernet port 1/7:

Router# clear mvr receiver-ports GigabitEthernet 1/7

Router# show mvr receiver-ports GigabitEthernet 1/7

Joins: v1,v2,v3 counter shows total IGMP joins

       v3 counter shows IGMP joins received with both MVR and non-MVR groups

Port   VLAN Status          Immediate            Joins

                               Leave         (v1,v2,v3)     (v3)

----   ---- -------------  ----------   ---------- -----------

Gi1/7   202 INACTIVE/UP    ENABLED                 0             0

Tip For additional information about Cisco Catalyst 6500 Series Switches (including configuration examples and troubleshooting information), see the documents listed on this page:

http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.html

Participate in the Technical Documentation Ideas forum