Catalyst Supervisor Engine 32 PISA IOS Software Configuration Guide, 12.2ZY

Configuring IPv4 Multicast VPN Support

This chapter describes how to configure IPv4 Multicast Virtual Private Network (MVPN) support on Catalyst 6500 series switches.

Note For complete syntax and usage information for the commands used in this chapter, refer to the Catalyst Supervisor Engine 32 PISA Cisco IOS Command Reference, Release 12.2ZY, at this URL:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2ZY/command/reference/cmdref.html

This chapter contains these sections:

•Understanding How MVPN Works

•MVPN Configuration Guidelines and Restrictions

•Configuring MVPN

Understanding How MVPN Works

These sections describe MVPN:

•MVPN Overview

•Multicast Routing and Forwarding and Multicast Domains

•Multicast Distribution Trees

•Multicast Tunnel Interfaces

•PE Router Routing Table Support for MVPN

•Multicast Distributed Switching Support

•Hardware-Assisted IPv4 Multicast

MVPN Overview

MVPN is a standards-based feature that transmits IPv4 multicast traffic across an MPLS VPN cloud. MVPN on Catalyst 6500 series switches uses the existing PFC3B hardware support for IPv4 multicast traffic to forward multicast traffic over VPNs at wire speeds. MVPN adds support for IPv4 multicast traffic over Layer 3 IPv4 VPNs to the existing IPv4 unicast support.

MVPN routes and forwards multicast packets for each individual VPN routing and forwarding (VRF) instance, as well as transmitting the multicast packets through VPN tunnels across the service provider backbone.

MVPN is an alternative to IP-in-IP generic route encapsulation (GRE) tunnels. GRE tunnels are not a readily scalable solution and they are limited in the granularity they provide to customers.

Multicast Routing and Forwarding and Multicast Domains

MVPN adds multicast routing information to the VPN routing and forwarding table. When a provider-edge (PE) router receives multicast data or control packets from a customer-edge (CE) router, forwarding is performed according to the information in the multicast VRF (MVRF).

Note MVRF is also commonly referred to as multicast over VRF-lite.

Each MVRF maintains the routing and forwarding information that is needed for its particular VRF instance. An MVRF is created and configured in the same way as existing VRFs, except multicast routing is also enabled on each MVRF.

A multicast domain constitutes the set of hosts that can send multicast traffic to each other within the MPLS network. For example, the multicast domain for a customer that wanted to send certain types of multicast traffic to all global employees would consist of all CE routers associated with that enterprise.

Multicast Distribution Trees

The MVPN feature establishes at least one multicast distribution tree (MDT) for each multicast domain. The MDT provides the information needed to interconnect the same MVRFs that exist on the different PE routers.

MVPN supports two MDT types:

•Default MDT—The default MDT is a permanent channel for PIM control messages and low-bandwidth streams between all PE routers in a particular multicast domain. All multicast traffic in the default MDT is replicated to every other PE router in the domain. Each PE router is logically seen as a PIM neighbor (one hop away) from every other PE router in the domain.

•Data MDT—Data MDTs are optional. If enabled, they are dynamically created to provide optimal paths for high-bandwidth transmissions, such as full-motion video, that do not need to be sent to every PE router. This allows for on-demand forwarding of high-bandwidth traffic between PE routers, so as to avoid flooding every PE router with every high-bandwidth stream that might be created.

To create data MDTs, each PE router that is forwarding multicast streams to the backbone periodically examines the traffic being sent in each default MDT as follows:

1. Each PE router periodically samples the multicast traffic (approximately every 10 seconds for software switching, and 90 seconds for hardware switching) to determine whether a multicast stream has exceeded the configured threshold. (Depending on when the stream is sampled, this means that in a worst-case scenario, it could take up to 180 seconds before a high-bandwidth stream is detected.)

Note Data MDTs are created only for (S, G) multicast route entries within the VRF multicast routing table. They are not created for (*, G) entries.

1. If a particular multicast stream exceeds the defined threshold, the sending PE router dynamically creates a data MDT for that particular multicast traffic.

2. The sending PE router then transmits a DATA-MDT JOIN request (which is a User Datagram Protocol (UDP) message to port 3232) to the other PE routers, informing them of the new data MDT.

3. Receiving PE routers examine their VRF routing tables to determine if they have any customers interested in receiving this data stream. If so, they use the PIM protocol to transmit a PIM JOIN message for this particular data MDT group (in the global table PIM instance) to accept the stream. Routers that do not currently have any customers for this stream still cache the information, in case any customers request it later on.

4. Three seconds after sending the DATA-MDT JOIN message, the sending PE router removes the high-bandwidth multicast stream from the default MDT and begins transmitting it over the new data MDT.

5. The sending PE router continues to send a DATA-MDT JOIN message every 60 seconds, as long as the multicast stream continues to exceed the defined threshold. If the stream falls below the threshold for more than 60 seconds, the sending PE router stops sending the DATA-MDT JOIN messages, and moves the stream back to the default MDT.

6. Receiving routers age out the cache information for the default MDT when they do not receive a DATA-MDT JOIN message for more than three minutes.

Data MDTs allow for high-bandwidth sources inside the VPN while still ensuring optimal traffic forwarding in the MPLS VPN core.

Note For technical information about the DATA-MDT JOIN message and other aspects of the data MDT creation and usage, see the Internet-Draft, Multicast in MPLS/BGP IP VPNs, by Eric C. Rosen et al.

In the following example, a service provider has a multicast customer with offices in San Jose, New York, and Dallas. The San Jose site is transmitting a one-way multicast presentation. The service provider network supports all three sites associated with this customer, in addition to the Houston site of a different enterprise customer.

The default MDT for the enterprise customer consists of provider routers P1, P2, and P3 and their associated PE routers. Although PE4 is interconnected to these other routers in the MPLS core, PE4 is associated with a different customer and is therefore not part of the default MDT.

Figure 22-1 shows the situation in this network when no one outside of San Jose has joined the multicast broadcast, which means that no data is flowing along the default MDT. Each PE router maintains a PIM relationship with the other PE routers over the default MDT, as well as a PIM relationship with its directly attached PE routers.

Figure 22-1 Default Multicast Distribution Tree Overview

If an employee in New York joins the multicast session, the PE router associated for the New York site sends a join request that flows across the default MDT for the multicast domain. The PE router associated with the multicast session source (PE1) receives the request. Figure 22-2 shows how the PE router forwards the request to the CE router associated with the multicast source (CE1a).

Figure 22-2 Initializing the Data MDT

The CE router (CE1a) starts sending the multicast data to the associated PE router (PE1), which recognizes that the multicast data exceeds the bandwidth threshold at which a data MDT should be created. PE1 then creates a data MDT and sends a message to all routers using the default MDT that contains information about the data MDT.

Approximately three seconds later, PE1 begins sending the multicast data for that particular stream using the data MDT. Because only PE2 has receivers who are interested in this source, only PE2 joins the data MDT and receives traffic on it.

Multicast Tunnel Interfaces

The PE router creates a multicast tunnel interface (MTI) for each multicast VRF (MVRF) in the multicast domain. The MVRF uses the tunnel interface to access the multicast domain to provide a conduit that connects an MVRF and the global MVRF.

On the router, the MTI is a tunnel interface (created with the interface tunnel command) with a class D multicast address. All PE routers that are configured with a default MDT for this MVRF create a logical network in which each PE router appears as a PIM neighbor (one hop away) to every other PE router in the multicast domain, regardless of the actual physical distance between them.

The MTI is automatically created when an MVRF is configured. The BGP peering address is assigned as the MTI interface source address, and the PIM protocol is automatically enabled on each MTI.

When the router receives a multicast packet from the customer side of the network, it uses the incoming interface's VRF to determine which MVRFs should receive it. The router then encapsulates the packet using GRE encapsulation. When the router encapsulates the packet, it sets the source address to that of the BGP peering interface and sets the destination address to the multicast address of the default MDT, or to the source address of the data MDT if configured. The router then replicates the packet as needed for forwarding on the appropriate number of MTI interfaces.

When the router receives a packet on the MTI interface, it uses the destination address to identify the appropriate default MDT or data MDT, which in turn identifies the appropriate MVRF. It then decapsulates the packet and forwards it out the appropriate interfaces, replicating it as many times as are necessary.

Note•Unlike other tunnel interfaces that are commonly used on Cisco routers, the MVPN MTI is classified as a LAN interface, not a point-to-point interface. The MTI interface is not configurable, but you can use the show interface tunnel command to display its status.

•The MTI interface is used exclusively for multicast traffic over the VPN tunnel.

•The tunnel does not carry unicast routed traffic.

PE Router Routing Table Support for MVPN

Each PE router that supports the MVPN feature uses the following routing tables to ensure that the VPN and MVPN traffic is routed correctly:

•Default routing table—Standard routing table used in all Cisco routers. This table contains the routes that are needed for backbone traffic and for non-MPLS VPN unicast and multicast traffic (including Generic Routing Encapsulation (GRE) multicast traffic).

•VPN routing/forwarding (VRF) table—Routing table created for each VRF instance. Responsible for routing the unicast traffic between VPNs in the MPLS network.

•Multicast VRF (MVRF) table—Multicast routing table and multicast routing protocol instance created for each VRF instance. Responsible for routing the multicast traffic in the multicast domain of the network. This table also includes the multicast tunnel interfaces that are used to access the multicast domain.

Multicast Distributed Switching Support

MVPN supports multicast distributed switching (MDS) for multicast support on a per-interface and a per-VRF basis. When configuring MDS, you must make sure that no interface (including loopback interfaces) has the no ip mroute-cache command configured.

Hardware-Assisted IPv4 Multicast

Hardware acceleration for IPv4 multicast over VPN traffic forwards multicast traffic to the appropriate VPNs at wire speed without increased PISA CPU utilization.

In a customer VRF, hardware acceleration supports multicast traffic in PIM dense, PIM sparse, PIM bidirectional, and PIM Source Specific Multicast (SSM) modes.

In the service provider core, hardware acceleration supports multicast traffic in PIM sparse, PIM bidirectional, and PIM SSM modes. In the service provider core, hardware acceleration does not support multicast traffic in PIM dense mode.

MVPN Configuration Guidelines and Restrictions

When configuring MVPN, follow these guidelines and restrictions:

•All PE routers in the multicast domain need to be running a Cisco IOS software image that supports the MVPN feature. There is no requirement for MVPN support on the P and CE routers.

•Support for IPv4 multicast traffic must also be enabled on all backbone routers.

•The Border Gateway Protocol (BGP) routing protocol must be configured and operational on all routers supporting multicast traffic. In addition, BGP extended communities must be enabled (using the neighbor send-community both or neighbor send-community extended command) to support the use of MDTs in the network.

•Only ingress replication is supported when MVPN is configured. If the switch is currently configured for egress replication, it is forced into ingress replication when the first MVRF is configured.

•When the switch is acting as a PE, and receives a multicast packet from a customer router with a time-to-live (TTL) value of 2, it drops the packet instead of encapsulating it and forwarding it across the MVPN link. Because such packets would normally be dropped by the PE at the other end of the MVPN link, this does not affect traffic flow.

•If the core multicast routing uses SSM, then the data and default multicast distribution tree (MDT) groups must be configured within the SSM range of IPv4 addresses.

•The update source interface for the BGP peerings must be the same for all BGP peerings configured on the router in order for the default MDT to be configured properly. If you use a loopback address for BGP peering, then PIM sparse mode must be enabled on the loopback address.

•The ip mroute-cache command must be enabled on the loopback interface used as the BGP peering interface in order for distributed multicast switching to function on the platforms that support it. The no ip mroute-cache command must not be present on these interfaces.

•Data MDTs are not created for VRF PIM dense mode multicast streams because of the flood and prune nature of dense mode multicast flows and the resulting periodic bring-up and tear-down of such data MDTs.

•Data MDTs are not created for VRF PIM bidirectional mode because source information is not available.

•MVPN does not support multiple BGP peering update sources, and configuring them can break MVPN RPF checking. The source IPv4 address of the MVPN tunnels is determined by the highest IPv4 address used for the BGP peering update source. If this IPv4 address is not the IPv4 address used as the BGP peering address with the remote PE router, MVPN will not function properly.

•MDT tunnels do not carry unicast traffic.

•Although MVPN uses the infrastructure of MPLS VPN networks, you cannot apply MPLS tags or labels to multicast traffic over the VPNs.

•Each MVRF that is configured with a default MDT uses three hidden VLANs (one each for encapsulation, decapsulation, and interface), in addition to external, user-visible VLANs. This means that an absolute maximum of 1,000 MVRFs are supported on each router. (MVRFs without a configured MDT still use one internal VLAN, so unused MVRFs should be deleted to conserve VLAN allocation.)

•Because MVPN uses MPLS, MVPN supports only the RPR redundancy mode.

•If your MPLS VPN network already contains a network of VRFs, you do not need to delete them or recreate them to be able to support MVRF traffic. Instead, configure the mdt default and mdt data commands, as listed in the following procedure, to enable multicast traffic over the VRF.

•BGP should be already configured and operational on all routers that are sending or receiving multicast traffic. In addition, BGP extended communities must be enabled (using the neighbor send-community both or neighbor send-community extended command) to support the use of MDTs in the network.

•The same MVRF must be configured on each PE router that is to support a particular VPN connection.

•Each PE router that supports a particular MVRF must be configured with the same mdt default command.

•The switch supports only ingress replication when MVPN is configured. If a switch is currently configured for egress replication, it is forced into ingress replication when the first MVRF is configured. If a switch is currently configured for egress replication, we recommend performing this task only during scheduled maintenance periods, so that traffic disruption can be kept to a minimum.

Configuring MVPN

These sections describe how to configure MVPN:

•Forcing Ingress Multicast Replication Mode (Optional)

•Configuring a Multicast VPN Routing and Forwarding Instance

•Configuring Multicast VRF Routing

•Configuring Interfaces for Multicast Routing to Support MVPN

Note These configuration tasks assume that BGP is already configured and operational on all routers that are sending or receiving the multicast traffic. In addition, BGP extended communities must be enabled (using the neighbor send-community both or neighbor send-community extended command) to support the use of MDTs in the network.

Forcing Ingress Multicast Replication Mode (Optional)

The MVPN feature supports only ingress multicast replication mode. If the switch is currently configured for egress replication, it is forced into ingress replication when the first MVRF is configured. This change in replication mode automatically purges all forwarding entries in the hardware, temporarily forcing the switch into software switching until the table entries can be rebuilt.

To avoid disrupting customer traffic, we recommend verifying that the switch is already in ingress multicast replication mode before configuring any MVRFs.

This example shows how to verify the multicast replication mode:

Router# show mls ip multicast capability 

Current mode of replication is Ingress 

auto replication mode detection is ON 

 Slot           Multicast replication capability

    2                       Egress

    5                       Egress

    6                       Egress

    8                       Ingress

    9                       Ingress

Router# 

If the current replication mode is egress or if any of the switching modules are capable of egress replication mode, configure ingress replication mode during a scheduled maintenance period to minimize the disruption of customer traffic.

To configure ingress multicast replication mode, perform this task:

This example shows how to configure ingress multicast replication mode and verify the configuration:

Router(config)# mls ip multicast replication-mode ingress 

Router(config)# do show mls ip multicast capability | include Current

Current mode of replication is Ingress 

Configuring a Multicast VPN Routing and Forwarding Instance

These sections describe how to configure a multicast VPN routing and forwarding (MVRF) instance for each VPN connection on each PE router that is to handle the traffic for each particular VPN connection that is to transmit or receive multicast traffic:

•Configuring a VRF Entry

•Configuring the Route Distinguisher

•Configuring the Route-Target Extended Community

•Configuring the Default MDT

•Configuring Data MDTs (Optional)

•Enabling Data MDT Logging

•Sample Configuration

•Displaying VRF Information

Configuring a VRF Entry

To configure a VRF entry, perform this task:

This example show how to configure a VRF named blue and verify the configuration:

Router# configure terminal 

Router(config)# ip vrf blue 

Router(config-vrf)# do show ip vrf blue 

Name                             Default RD          Interfaces

  blue                             <not set> 

Configuring the Route Distinguisher

To configure the route distinguisher, perform this task:

Router(config-vrf)# rd route_distinguisher 

When configuring the route distinguisher, enter the route distinguisher in one of the following formats:

•16-bit AS number:your 32-bit number (101:3)

•32-bit IPv4 address:your 16-bit number (192.168.122.15:1)

This example show how to configure 55:1111 as the route distinguisher and verify the configuration:

Router(config-vrf)# rd 55:1111 

Router(config-vrf)# do show ip vrf blue 

Name                             Default RD          Interfaces

blue                             55:1111 

Configuring the Route-Target Extended Community

To configure the route-target extended community, perform this task:

When configuring the route-target extended community, note the following information:

•import—Imports routing information from the target VPN extended community.

•export—Exports routing information to the target VPN extended community.

•both—Imports and exports.

•route_target_ext_community—Adds the 48-bit route-target extended community to the VRF. Enter the number in one of the following formats:

–16-bit AS number:your 32-bit number (101:3)

–32-bit IPv4 address:your 16-bit number (192.168.122.15:1)

This example shows how to configure 55:1111 as the import and export route-target extended community and verify the configuration:

Router(config-vrf)# route-target both 55:1111

Router(config-vrf)# do show ip vrf detail

VRF blue; default RD 55:1111; default VPNID <not set>

VRF Table ID = 1

No interfaces

Connected addresses are not in global routing table

Export VPN route-target communities

RT:55:1111

Import VPN route-target communities

RT:55:1111

No import route-map

No export route-map

CSC is not configured.

Configuring the Default MDT

To configure the default MDT, perform this task:

When configuring the default MDT, note the following information:

•The group_address is the multicast IPv4 address of the default MDT group. This address serves as an identifier for the MVRF community, because all provider-edge (PE) routers configured with this same group address become members of the group, which allows them to receive the PIM control messages and multicast traffic that are sent by other members of the group.

•This same default MDT must be configured on each PE router to enable the PE routers to receive multicast traffic for this particular MVRF.

This example shows how to configure 239.1.1.1 as the default MDT:

Router(config-vrf)# mdt default 239.1.1.1

Configuring Data MDTs (Optional)

To configure optional data MDTs, perform this task:

When configuring optional data MDTs, note the following information:

•group_address1—Multicast group address. The address can range from 224.0.0.1 to 239.255.255.255, but cannot overlap the address that has been assigned to the default MDT.

•wildcard_bits—Wildcard bit mask to be applied to the multicast group address to create a range of possible addresses. This allows you to limit the maximum number of data MDTs that each MVRF can support.

•threshold threshold_value—(Optional) Defines the threshold value in kilobits, at which multicast traffic should be switched from the default MDT to the data MDT. The threshold_value parameter can range from 1 through 4294967 kilobits.

•list access_list—(Optional) Specifies an access list name or number to be applied to this traffic.

This example shows how to configure a data MDT:

Router(config-vrf)# mdt data 239.1.2.0 0.0.0.3 threshold 10

Enabling Data MDT Logging

To enable data MDT logging, perform this task:

This example shows how to enable data MDT logging:

Router(config-vrf)# mdt log-reuse

Sample Configuration

The following excerpt from a configuration file shows typical VRF configurations for a range of VRFs. To simplify the display, only the starting and ending VRFs are shown.

!

ip vrf mvpn-cus1

 rd 200:1

 route-target export 200:1

 route-target import 200:1

 mdt default 239.1.1.1

!

ip vrf mvpn-cus2

 rd 200:2

 route-target export 200:2

 route-target import 200:2

 mdt default 239.1.1.2

!

ip vrf mvpn-cus3

 rd 200:3

 route-target export 200:3

 route-target import 200:3

 mdt default 239.1.1.3

!

...

ip vrf mvpn-cus249

 rd 200:249

 route-target export 200:249

 route-target import 200:249

 mdt default 239.1.1.249

 mdt data 239.1.1.128 0.0.0.7 

Displaying VRF Information

To display all of the VRFs that are configured on the switch, use the show ip vrf command:

Router# show ip vrf 

  Name                             Default RD          Interfaces

  green                            1:52                GigabitEthernet6/1

  red                              200:1               GigabitEthernet1/1

                                                       GigabitEthernet3/16

                                                       Loopback2

Router#

To display information about the MDTs that are currently configured for all MVRFs, use the show ip pim mdt command. The following example shows typical output for this command:

Router# show ip pim mdt 

  MDT Group       Interface   Source                   VRF

* 227.1.0.1       Tunnel1     Loopback0                BIDIR01 

* 227.2.0.1       Tunnel2     Loopback0                BIDIR02 

* 228.1.0.1       Tunnel3     Loopback0                SPARSE01 

* 228.2.0.1       Tunnel4     Loopback0                SPARSE02 

Note To display information about a specific tunnel interface, use the show interface tunnel command. The IPv4 address for the tunnel interface is the multicast group address for the default MDT of the MVRF.

To display additional information about the MDTs, use the show mls ip multicast mdt command. The following example shows typical output for this command:

Router# show mls ip multicast mdt 

  State: H - Hardware Installed, I - Install Pending, D - Delete Pending, 

       Z - Zombie

                MMLS

  VRF           VPN-ID            MDT INFO                      MDT Type     State

   BIDIR01HWRP       1            (10.10.10.9, 227.1.0.1)       default      H

   BIDIR01SWRP       2            (10.10.10.9, 227.2.0.1)       default      H

  SPARSE01HWRP       3            (10.10.10.9, 228.1.0.1)       default      H

  SPARSE01SWRP       4            (10.10.10.9, 228.2.0.1)       default      H

           red       5               (6.6.6.6, 234.1.1.1)       default      H

           red       5            (131.2.1.2, 228.1.1.75)   data (send)      H

           red       5            (131.2.1.2, 228.1.1.76)   data (send)      H

           red       5            (131.2.1.2, 228.1.1.77)   data (send)      H

           red       5            (131.2.1.2, 228.1.1.78)   data (send)      H

Router# 

To display routing information for a particular VRF, use the show ip route vrf command:

Router# show ip route vrf red 

Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP

       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area

       * - candidate default, U - per-user static route, o - ODR

       P - periodic downloaded static route

Gateway of last resort is not set

     2.0.0.0/32 is subnetted, 1 subnets

C       2.2.2.2 is directly connected, Loopback2

     3.0.0.0/32 is subnetted, 1 subnets

B       3.3.3.3 [200/0] via 3.1.1.3, 00:20:09

C    21.0.0.0/8 is directly connected, GigabitEthernet3/16

B    22.0.0.0/8 [200/0] via 3.1.1.3, 00:20:09

Router# 

To display information about the multicast routing table and tunnel interface for a particular MVRF, use the show ip mroute vrf command. The following example shows typical output for a MVRF named BIDIR01:

Router# show ip mroute vrf BIDIR01 

IP Multicast Routing Table

Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,

       L - Local, P - Pruned, R - RP-bit set, F - Register flag,

       T - SPT-bit set, J - Join SPT, M - MSDP created entry,

       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,

       U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel

       Y - Joined MDT-data group, y - Sending to MDT-data group

Outgoing interface flags: H - Hardware switched

 Timers: Uptime/Expires

 Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 228.1.0.1), 00:16:25/stopped, RP 10.10.10.12, flags: SJCF

  Incoming interface: Tunnel1, RPF nbr 10.10.10.12, Partial-SC

  Outgoing interface list:

    GigabitEthernet3/1.3001, Forward/Sparse-Dense, 00:16:25/00:02:49, H

(6.9.0.100, 228.1.0.1), 00:14:13/00:03:29, flags: FT

  Incoming interface: GigabitEthernet3/1.3001, RPF nbr 0.0.0.0, RPF-MFD

  Outgoing interface list:

    Tunnel1, Forward/Sparse-Dense, 00:14:13/00:02:46, H

Router# 

Note In this example, the show ip mroute vrf command shows that Tunnel1 is the MDT tunnel interface (MTI) being used by this VRF.

Configuring Multicast VRF Routing

These sections describe how to configure multicast routing to support MVPN:

•Enabling IPv4 Multicast Routing Globally

•Enabling IPv4 Multicast VRF Routing

•Configuring a PIM VRF Register Message Source Address

•Specifying the PIM VRF Rendezvous Point (RP) Address

•Configuring a Multicast Source Discovery Protocol (MSDP) Peer

•Enabling IPv4 Multicast Header Storage

•Configuring the Maximum Number of Multicast Routes

•Sample Configuration

•Displaying IPv4 Multicast VRF Routing Information

Note BGP should be already configured and operational on all routers that are sending or receiving multicast traffic. In addition, BGP extended communities must be enabled (using the neighbor send-community both or neighbor send-community extended command) to support the use of MDTs in the network.

Enabling IPv4 Multicast Routing Globally

To enable IPv4 multicast routing globally, perform this task:

This example show how to enable IPv4 multicast routing globally:

Router# configure terminal

Router(config)# ip multicast-routing

Enabling IPv4 Multicast VRF Routing

To enable IPv4 multicast VRF routing, perform this task:

When enabling IPv4 multicast VRF routing, note the following information:

•vrf_name—Specifies a particular VRF for multicast routing. The vrf_name should refer to a VRF that has been previously created, as specified in the "Configuring a Multicast VPN Routing and Forwarding Instance" section.

•distributed—(Optional) Enables Multicast Distributed Switching (MDS).

This example show how to enable IPv4 multicast VRF routing:

Router# configure terminal

Router(config)# ip multicast-routing vrf blue

Configuring a PIM VRF Register Message Source Address

To configure a PIM VRF register message source address, perform this task:

Router(config)# ip pim vrf vrf_name register-source 
interface_type interface_number 

This example show how to configure a PIM VRF register message source address:

Router(config)# ip pim vrf blue register-source loopback 3

Specifying the PIM VRF Rendezvous Point (RP) Address

To specify the PIM VRF RP address, perform this task:

Router(config)# ip pim vrf vrf_name rp-address 
rp_address [access_list] [override] [bidir] 

When specifying the PIM VRF RP address, note the following information:

•vrf vrf_name—(Optional) Specifies a particular VRF instance to be used.

•rp_address—Unicast IP address for the PIM RP router.

•access_list—(Optional) Number or name of an access list that defines the multicast groups for the RP.

•override—(Optional) In the event of conflicting RP addresses, this particular RP overrides any RP that is learned through Auto-RP.

•bidir—(Optional) Specifies that the multicast groups specified by the access_list argument are to operate in bidirectional mode. If this option is not specified, the groups operate in PIM sparse mode.

•Use bidirectional mode whenever possible, because it offers better scalability.

This example show how to specify the PIM VRF RP address:

Router(config)# ip pim vrf blue rp-address 198.196.100.33

Configuring a Multicast Source Discovery Protocol (MSDP) Peer

To configure an MSDP peer, perform this task:

When configuring an MSDP peer, note the following information:

•vrf vrf_name—Specifies a particular VRF instance to be used.

•{peer_name | peer_address}—Domain Name System (DNS) name or IP address of the MSDP peer router.

•connect-source interface_type interface_number—Interface name and number for the interface whose primary address is used as the source IP address for the TCP connection.

•remote-as ASN—(Optional) Autonomous system number of the MSDP peer. This is for display-only purposes.

This example show how to configure an MSDP peer:

Router(config)# ip msdp peer router.cisco.com connect-source fastethernet 1/1 remote-as 109

Enabling IPv4 Multicast Header Storage

To enable IPv4 multicast header storage, perform this task:

When enabling IPv4 multicast header storage, note the following information:

•vrf vrf_name—Allocates a buffer for the specified VRF.

•rtp—(Optional) Also caches Real-Time Transport Protocol (RTP) headers.

•The buffers can be displayed with the show ip mpacket command.

This example show how to enable IPv4 multicast header storage:

Router(config)# ip multicast vrf blue cache-headers 

Configuring the Maximum Number of Multicast Routes

To configure the maximum number of multicast routes, perform this task:

When configuring the maximum number of routes, note the following information:

•vrf vrf_name— Enables route limiting for the specified VRF.

•limit—The number of multicast routes that can be added. The range is from 1 to 2147483647, with a default of 2147483647.

•threshold—(Optional) Number of multicast routes that can be added before a warning message occurs. The valid range is from 1 to the value of the limit parameter.

This example show how to configure the maximum number of multicast routes:

Router(config)# ip multicast vrf blue route-limit 200000 20000

Configuring IPv4 Multicast Route Filtering

To configure IPV4 multicast route filtering, perform this task:

This example show how to configure IPV4 multicast route filtering:

Router(config)# ip multicast mrinfo-filter 101

Sample Configuration

The following excerpt from a configuration file shows the minimum configuration that is needed to support multicast routing for a range of VRFs. To simplify the display, only the starting and ending VRFs are shown.

!

ip multicast-routing 

ip multicast-routing vrf lite 

ip multicast-routing vrf vpn201 

ip multicast-routing vrf vpn202 

...

ip multicast-routing vrf vpn249 

ip multicast-routing vrf vpn250 

ip multicast cache-headers

...

ip pim rp-address 192.0.1.1

ip pim vrf lite rp-address 104.1.1.2

ip pim vrf vpn201 rp-address 192.200.1.1

ip pim vrf vpn202 rp-address 192.200.2.1

...

ip pim vrf vpn249 rp-address 192.200.49.6

ip pim vrf vpn250 rp-address 192.200.50.6

... 

Displaying IPv4 Multicast VRF Routing Information

To display the known PIM neighbors for a particular MVRF, use the show ip pim vrf neighbor command:

Router# show ip pim vrf 98 neighbor 

PIM Neighbor Table

Neighbor          Interface                Uptime/Expires    Ver   DR

Address                                                            Prio/Mode

40.60.0.11        Tunnel96                 00:00:31/00:01:13 v2    1 / S

40.50.0.11        Tunnel96                 00:00:54/00:00:50 v2    1 / S

Router#

Configuring Interfaces for Multicast Routing to Support MVPN

These sections describe how to configure interfaces for multicast routing to support MVPN:

•Multicast Routing Configuration Overview

•Configuring PIM on an Interface

•Configuring an Interface for IPv4 VRF Forwarding

•Sample Configuration

Multicast Routing Configuration Overview

Protocol Independent Multicast (PIM) must be configured on all interfaces that are being used for IPv4 multicast traffic. In a VPN multicast environment, you should enable PIM on at least all of the following interfaces:

•Physical interface on a provider edge (PE) router that is connected to the backbone.

•Loopback interface that is used for BGP peering.

•Loopback interface that is used as the source for the sparse PIM rendezvous point (RP) router address.

In addition, you must also associate MVRFs with those interfaces over which they are going to forward multicast traffic.

BGP should be already configured and operational on all routers that are sending or receiving multicast traffic. In addition, BGP extended communities must be enabled (using the neighbor send-community both or neighbor send-community extended command) to support the use of MDTs in the network.

Configuring PIM on an Interface

To configure PIM on an interface, perform this task

Router(config-if)# ip pim {dense-mode | 
sparse-mode | sparse-dense-mode} 

When configuring PIM on an interface, note the following information:

•You can use one of these interface types:

–A physical interface on a provider edge (PE) router that is connected to the backbone.

–A loopback interface that is used for BGP peering.

–A loopback interface that is used as the source for the sparse PIM network rendezvous point (RP) address.

•These are the PIM modes:

–dense-mode—Enables dense mode of operation.

–sparse-mode—Enables sparse mode of operation.

–sparse-dense-mode—Enables sparse mode if the multicast group has an RP router defined, or enables dense mode if an RP router is not defined.

•Use sparse-mode for the physical interfaces of all PE routers that are connected to the backbone, and on all loopback interfaces that are used for BGP peering or as the source for RP addressing.

This example shows how to configure PIM sparse mode on a physical interface:

Router# configure terminal

interface gigabitethernet 10/1

Router(config-if)# ip pim sparse-mode

This example shows how to configure PIM sparse mode on a loopback interface:

Router# configure terminal

Router(config)# interface loopback 2

Router(config-if)# ip pim sparse-mode

Configuring an Interface for IPv4 VRF Forwarding

To configure an interface for IPv4 VRF forwarding, perform this task:

Router(config-if)# ip vrf forwarding vrf_name 

This example shows how to configure the interface for VRF blue forwarding:

Router(config-if)# ip vrf forwarding blue

Sample Configuration

The following excerpt from a configuration file shows the interface configuration, along with the associated MVRF configuration, to enable multicast traffic over a single MVRF:

ip multicast-routing vrf blue 

ip multicast-routing

ip vrf blue 

 rd 100:27

 route-target export 100:27

 route-target import 100:27

 mdt default 239.192.10.2	

interface GigabitEthernet1/1

 description blue connection

 ip vrf forwarding blue 

 ip address 192.168.2.26 255.255.255.0

 ip pim sparse-mode

interface GigabitEthernet1/15

 description Backbone connection

 ip address 10.8.4.2 255.255.255.0

 ip pim sparse-mode

ip pim vrf blue rp-address 192.7.25.1

ip pim rp-address 10.1.1.1 

Sample Configurations for MVPN

This section contains the following sample configurations for the MVPN feature:

•MVPN Configuration with Default MDTs Only

•MVPN Configuration with Default and Data MDTs

MVPN Configuration with Default MDTs Only

The following excerpt from a configuration file shows the lines that are related to the MVPN configuration for three MVRFs. (The required BGP configuration is not shown.)

!

version 12.2

service timestamps debug datetime msec

service timestamps log datetime msec

service password-encryption

service compress-config

!

hostname MVPN Router 

!

boot system flash slot0:

logging snmp-authfail

!

ip subnet-zero

!

!

no ip domain-lookup

ip host tftp 223.255.254.238

!

ip vrf mvpn-cus1

 rd 200:1

 route-target export 200:1

 route-target import 200:1

 mdt default 239.1.1.1

!

ip vrf mvpn-cus2

 rd 200:2

 route-target export 200:2

 route-target import 200:2

 mdt default 239.1.1.2

!

ip vrf mvpn-cus3

 rd 200:3

 route-target export 200:3

 route-target import 200:3

 mdt default 239.1.1.3

!

ip multicast-routing 

ip multicast-routing vrf mvpn-cus1 

ip multicast-routing vrf mvpn-cus2 

ip multicast-routing vrf mvpn-cus3 

ip multicast multipath

frame-relay switching

mpls label range 4112 262143

mpls label protocol ldp

mpls ldp logging neighbor-changes

mpls ldp explicit-null

mpls traffic-eng tunnels

tag-switching tdp discovery directed-hello accept from 1

tag-switching tdp router-id Loopback0 force

mls ip multicast replication-mode ingress

mls ip multicast flow-stat-timer 9

mls ip multicast bidir gm-scan-interval 10

mls flow ip destination

no mls flow ipv6

mls rate-limit unicast cef glean 10 10

mls qos

mls cef error action freeze

...

vlan internal allocation policy ascending

vlan access-log ratelimit 2000

!

vlan 2001-2101,3501-3700,4001,4051-4080,4093 

!

!

!

interface Loopback0

 ip address 201.252.1.14 255.255.255.255

 ip pim sparse-dense-mode

!

interface Loopback1

 ip address 209.255.255.14 255.255.255.255

!

interface Loopback10

 ip vrf forwarding mvpn-cus1

 ip address 210.101.255.14 255.255.255.255

!

interface Loopback11

 ip vrf forwarding mvpn-cus1

 ip address 210.111.255.14 255.255.255.255

 ip pim sparse-dense-mode

!

interface Loopback12

 ip vrf forwarding mvpn-cus1

 ip address 210.112.255.14 255.255.255.255

...

!

interface GigabitEthernet3/3

 mtu 9216

 ip vrf forwarding mvpn-cus3

 ip address 172.10.14.1 255.255.255.0

 ip pim sparse-dense-mode

!

...

!

interface GigabitEthernet3/19

 ip vrf forwarding mvpn-cus2

 ip address 192.16.4.1 255.255.255.0

 ip pim sparse-dense-mode

 ip igmp static-group 229.1.1.1

 ip igmp static-group 229.1.1.2

 ip igmp static-group 229.1.1.4

!

interface GigabitEthernet3/20

 ip vrf forwarding mvpn-cus1

 ip address 192.16.1.1 255.255.255.0

 ip pim sparse-dense-mode

!

...

MVPN Configuration with Default and Data MDTs

The following sample configuration includes three MVRFs that have been configured for both default and data MDTs. Only the configuration that is relevant to the MVPN configuration is shown.

...

!

ip vrf v1 

 rd 1:1

 route-target export 1:1

 route-target import 1:1

 mdt default 226.1.1.1

 mdt data 226.1.1.128 0.0.0.7 threshold 1

!

ip vrf v2

 rd 2:2

 route-target export 2:2

 route-target import 2:2

 mdt default 226.2.2.1

 mdt data 226.2.2.128 0.0.0.7

!

ip vrf v3

 rd 3:3

 route-target export 3:3

 route-target import 3:3

 mdt default 226.3.3.1

 mdt data 226.3.3.128 0.0.0.7

!

ip vrf v4

 rd 155.255.255.1:4

 route-target export 155.255.255.1:4

 route-target import 155.255.255.1:4

 mdt default 226.4.4.1

 mdt data 226.4.4.128 0.0.0.7

!

ip multicast-routing 

ip multicast-routing vrf v1 

ip multicast-routing vrf v2 

ip multicast-routing vrf v3 

ip multicast-routing vrf v4 

mpls label protocol ldp

mpls ldp logging neighbor-changes

tag-switching tdp router-id Loopback1

mls ip multicast replication-mode ingress

mls ip multicast bidir gm-scan-interval 10

no mls flow ip

no mls flow ipv6

mls cef error action freeze

!

!

!

!

!

...

vlan internal allocation policy ascending

vlan access-log ratelimit 2000

!

!

interface Loopback1

 ip address 155.255.255.1 255.255.255.255

 ip pim sparse-mode

!

interface Loopback4

 ip vrf forwarding v4

 ip address 155.255.4.4 255.255.255.255

 ip pim sparse-mode

!

interface Loopback11

 ip vrf forwarding v1

 ip address 155.255.255.11 255.255.255.255

 ip pim sparse-dense-mode

!

interface Loopback22

 ip vrf forwarding v2

 ip address 155.255.255.22 255.255.255.255

 ip pim sparse-mode

!

interface Loopback33

 ip vrf forwarding v3

 ip address 155.255.255.33 255.255.255.255

 ip pim sparse-mode

!

interface Loopback44

 no ip address

!

interface Loopback111

 ip vrf forwarding v1

 ip address 1.1.1.1 255.255.255.252

 ip pim sparse-dense-mode

 ip ospf network point-to-point

!

interface GigabitEthernet1/1

 description Gi1/1 - 155.50.1.155 255.255.255.0 - peer dut50 - mpls

 mtu 9216

 ip address 155.50.1.155 255.255.255.0

 ip pim sparse-mode

 tag-switching ip

!

interface GigabitEthernet1/2

 ip vrf forwarding v1

 ip address 155.1.2.254 255.255.255.0

 ip pim sparse-mode

!

interface GigabitEthernet1/3

 description Gi1/3 - 185.155.1.155/24 - vrf v1 stub peer 185.Gi1/3

 ip vrf forwarding v1

 ip address 185.155.1.155 255.255.255.0

 ip pim sparse-mode

!

...

!

interface GigabitEthernet1/48

 ip vrf forwarding v1

 ip address 157.155.1.155 255.255.255.0

 ip pim bsr-border

 ip pim sparse-dense-mode

!

interface GigabitEthernet6/1

 no ip address

 shutdown

!

interface GigabitEthernet6/2

 ip address 9.1.10.155 255.255.255.0

 media-type rj45

!

interface Vlan1

 no ip address

 shutdown

!

router ospf 11 vrf v1

 router-id 155.255.255.11

 log-adjacency-changes

 redistribute connected subnets tag 155

 redistribute bgp 1 subnets tag 155

 network 1.1.1.0 0.0.0.3 area 155

 network 155.255.255.11 0.0.0.0 area 155

 network 155.0.0.0 0.255.255.255 area 155

 network 157.155.1.0 0.0.0.255 area 0

!

router ospf 22 vrf v2

 router-id 155.255.255.22

 log-adjacency-changes

 network 155.255.255.22 0.0.0.0 area 155

 network 155.0.0.0 0.255.255.255 area 155

 network 157.155.1.0 0.0.0.255 area 0

!

router ospf 33 vrf v3

 router-id 155.255.255.33

 log-adjacency-changes

 network 155.255.255.33 0.0.0.0 area 155

!

router ospf 1

 log-adjacency-changes

 network 155.50.1.0 0.0.0.255 area 0

 network 155.255.255.1 0.0.0.0 area 155

!

router bgp 1

 bgp router-id 155.255.255.1

 no bgp default ipv4-unicast

 bgp log-neighbor-changes

 neighbor 175.255.255.1 remote-as 1

 neighbor 175.255.255.1 update-source Loopback1

 neighbor 185.255.255.1 remote-as 1

 neighbor 185.255.255.1 update-source Loopback1

 !

 address-family vpnv4

 neighbor 175.255.255.1 activate

 neighbor 175.255.255.1 send-community extended

 neighbor 185.255.255.1 activate

 neighbor 185.255.255.1 send-community extended

 exit-address-family

 !

 address-family ipv4 vrf v4

 no auto-summary

 no synchronization

 exit-address-family

 !

 address-family ipv4 vrf v3

 redistribute ospf 33

 no auto-summary

 no synchronization

 exit-address-family

 !

 address-family ipv4 vrf v2

 redistribute ospf 22

 no auto-summary

 no synchronization

 exit-address-family

 !

 address-family ipv4 vrf v1

 redistribute ospf 11

 no auto-summary

 no synchronization

 exit-address-family

!

ip classless

ip route 9.255.254.1 255.255.255.255 9.1.10.254

no ip http server

ip pim bidir-enable

ip pim rp-address 50.255.2.2 MCAST.MVPN.MDT.v2 override bidir

ip pim rp-address 50.255.3.3 MCAST.MVPN.MDT.v3 override bidir

ip pim rp-address 50.255.1.1 MCAST.MVPN.MDT.v1 override bidir

ip pim vrf v1 spt-threshold infinity

ip pim vrf v1 send-rp-announce Loopback11 scope 16 group-list MCAST.GROUP.BIDIR bidir

ip pim vrf v1 send-rp-discovery Loopback11 scope 16

ip pim vrf v1 bsr-candidate Loopback111 0

ip msdp vrf v1 peer 185.255.255.11 connect-source Loopback11

ip msdp vrf v1 cache-sa-state

!

!

ip access-list standard MCAST.ANYCAST.CE

 permit 2.2.2.2

ip access-list standard MCAST.ANYCAST.PE

 permit 1.1.1.1

ip access-list standard MCAST.BOUNDARY.VRF.v1

 deny   226.192.1.1

 permit any

ip access-list standard MCAST.GROUP.BIDIR

 permit 226.192.0.0 0.0.255.255

ip access-list standard MCAST.GROUP.SPARSE

 permit 226.193.0.0 0.0.255.255

ip access-list standard MCAST.MVPN.BOUNDARY.DATA.MDT

 deny   226.1.1.128

 permit any

ip access-list standard MCAST.MVPN.MDT.v1

 permit 226.1.0.0 0.0.255.255

ip access-list standard MCAST.MVPN.MDT.v2

 permit 226.2.0.0 0.0.255.255

ip access-list standard MCAST.MVPN.MDT.v3

 permit 226.3.0.0 0.0.255.255

ip access-list standard MCAST.MVPN.RP.v4

 permit 227.0.0.0 0.255.255.255

!

access-list 1 permit 226.1.1.1

access-list 2 deny   226.1.1.1

access-list 2 permit any

...