MPLS VPN的组播支持配置示例

简介

本文档提供配置多协议标签交换(MPLS)VPN组播支持的示例配置和一般准则。此功能在Cisco IOS®^软件版本12.0(23)S和12.2(13)T中引入。

先决条件

要求

在尝试此配置前，请保证您符合这些要求：

• 服务提供商必须具有支持组播的核心才能使用思科组播VPN功能。

使用的组件

本文档中的信息基于Cisco IOS软件版本12.2(13)T

注意：要获取有关此功能的平台支持的更新信息，请使用软件顾问(仅限注册客户)。 软件顾问会在为该功能添加新平台支持时动态更新支持平台的列表。

本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始（默认）配置。如果您使用的是真实网络，请确保您已经了解所有命令的潜在影响。

规则

有关文档规则的详细信息，请参阅 Cisco 技术提示规则。

背景信息

有关背景信息，请参阅Cisco IOS软件版本12.2(13)T新功能文档，了解MPLS VPN的IP组播支持。

配置

本部分提供有关如何配置本文档所述功能的信息。

网络图

本文档使用此图所示的网络设置。

配置

网络图表示服务提供商的主干。这包括路由器R2、R3和R4。主干配置为支持MPLS VPN。R2和R4是提供商边缘(PE)路由器，而R3是提供商(P)路由器。R1和R5代表属于同一VPN路由和转发(VRF)实例的客户边缘(CE)路由器，黄色。

要提供组播服务，必须配置主干以运行组播路由。为此选择的组播协议是协议无关组播(PIM),R3配置为交汇点(RP)。R2和R4还配置为将组播路由运行到VRF黄色。PIM稀疏 — 密集模式配置为PE和CE之间的组播路由协议。R2已配置为VRF黄色的RP。

为了测试组播连通性，R5的s0/0接口配置为加入组播组224.2.2.2。从R1的环回地址向224.2.2.2发送Ping。Internet控制消息协议(ICMP)回应是组播数据包，而ICMP应答是单播数据包，因为IP目的地址是R1的环回地址。

本文档中提供的配置包括：

• R1-(CE)

• R2-(PE)

• R3-(P)

• R4-(PE)

• R5-(CE)

version 12.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
!
clock timezone CET 1
ip subnet-zero
no ip domain lookup
!
ip multicast-routing 

!--- Enable multicast routing.

!
!
interface Loopback0
 ip address 100.0.0.1 255.255.255.255
!
interface Serial0/0
 ip address 10.1.0.1 255.255.255.0
 ip pim sparse-dense-mode

!--- PIM sparce-dense mode is used between the PE and CE. !--- PIM sparce-dense mode is the multicast routing protocol.

 
!
router rip
 version 2
 network 10.0.0.0
 network 100.0.0.0
 no auto-summary
!
ip classless
no ip http server
ip pim bidir-enable
!
!
!
!
line con 0
 exec-timeout 0 0
line aux 0
line vty 0 4
 login
!         
end

version 12.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R2
!
!
clock timezone CET 1
ip subnet-zero
no ip domain lookup
!
ip vrf yellow
 rd 2:200
 route-target export 2:200
 route-target import 2:200
 mdt default 239.1.1.1

!--- Configure the default Multicast Distribution Tree (MDT) !--- for VRF yellow.

 mdt data 239.2.2.0 0.0.0.255 threshold 1

!--- Configure the range global addresses for !--- data MDTs and the threshold.

ip multicast-routing 

!--- Enable global multicast routing.

ip multicast-routing vrf yellow 

!--- Enable multicast routing in VRF yellow.

ip cef
mpls label protocol ldp
tag-switching tdp router-id Loopback0
!
!
!
interface Loopback0
 ip address 50.0.0.2 255.255.255.255
 ip pim sparse-dense-mode


!--- Multicast needs to be enabled on loopback !--- interface. This is used as a source !--- for MPBGP sessions between PE routers that participate in MVPN.


!
interface Loopback100
 ip vrf forwarding yellow
 ip address 100.0.0.2 255.255.255.255
 ip pim sparse-dense-mode
!

!--- This router needs to be RP for !--- multicast in VRF yellow. Therefore, multicast !--- needs to be enabled on the interface which is used as RP.


!
interface Serial1/0
 ip vrf forwarding yellow
 ip address 10.1.0.2 255.255.255.0
 ip pim sparse-dense-mode

!--- Multicast is enabled on PE-CE interfaces in VRF.


!         
interface Serial2/0
 ip address 10.2.0.2 255.255.255.0
 ip pim sparse-dense-mode

!--- Service provider core needs to run multicast !--- to support MVPN services, !--- so multicast is enabled on PE-P links.


 tag-switching ip        
!         
router ospf 1
 router-id 50.0.0.2
 log-adjacency-changes
 network 10.0.0.0 0.255.255.255 area 0
 network 50.0.0.0 0.0.0.255 area 0
!
router rip
 version 2
 no auto-summary
 !
 address-family ipv4 vrf yellow
 version 2
 redistribute bgp 1
 network 10.0.0.0
 network 100.0.0.0
 default-metric 5
 no auto-summary
 exit-address-family
!
router bgp 1
 no synchronization
 no bgp default ipv4-unicast
 bgp log-neighbor-changes
 redistribute rip
 neighbor 50.0.0.4 remote-as 1
 neighbor 50.0.0.4 update-source Loopback0
 neighbor 50.0.0.4 activate
 neighbor 50.0.0.6 remote-as 1
 neighbor 50.0.0.6 update-source Loopback0
 neighbor 50.0.0.6 activate
 no auto-summary
 !
 address-family ipv4 vrf yellow
 redistribute connected
 redistribute rip
 no auto-summary
 no synchronization
 exit-address-family
 !
 address-family vpnv4
 neighbor 50.0.0.4 activate
 neighbor 50.0.0.4 send-community extended
 neighbor 50.0.0.6 activate
 neighbor 50.0.0.6 send-community extended
 no auto-summary
 exit-address-family
!         
ip classless
no ip http server
ip pim bidir-enable
ip pim vrf yellow send-rp-announce Loopback100 scope 100
ip pim vrf yellow send-rp-discovery Loopback100 scope 100

!--- Configure auto-RP. The R2's loopback !--- 100 is the RP in VRF yellow.

!
!
!
line con 0
 exec-timeout 0 0
line aux 0
line vty 0 4
 login
!
end

version 12.2 
service timestamps debug datetime msec 
service timestamps log datetime msec 
no service password-encryption 
! 
hostname R3 
! 
! 
clock timezone CET 1 
ip subnet-zero 
! 
ip multicast-routing  

!--- Enable global multicast routing.
 
ip cef 
mpls label protocol ldp 
tag-switching tdp router-id Loopback0 
! 
! 
! 
interface Loopback0 
 ip address 50.0.0.3 255.255.255.255 
 ip pim sparse-dense-mode 
! 
! 
interface Serial1/0 
 ip address 10.2.0.3 255.255.255.0 
 ip pim sparse-dense-mode

!--- Enable multicast on links to PE routers !--- which have MVPNs configured.

 
 tag-switching ip 
! 
interface Serial2/0 
 ip address 10.3.0.3 255.255.255.0 
 ip pim sparse-dense-mode 
 tag-switching ip 
! 
router ospf 1 
 router-id 50.0.0.3 
 log-adjacency-changes 
 network 10.0.0.0 0.255.255.255 area 0 
 network 50.0.0.0 0.0.0.255 area 0 
! 
ip classless 
no ip http server 
ip pim bidir-enable 
ip pim send-rp-announce Loopback0 scope 100 
ip pim send-rp-discovery Loopback0 scope 100 

!--- R3 is configured to announce itself as !--- the RP through auto-RP.
 
! 
! 
! 
! 
line con 0 
 exec-timeout 0 0 
line aux 0 
line vty 0 4 
 login  
! 
end

version 12.2 
service timestamps debug datetime msec 
service timestamps log datetime msec 
no service password-encryption 
! 
hostname R4 
! 
! 
clock timezone CET 1 
ip subnet-zero 
no ip domain lookup 
! 
ip vrf yellow 
 rd 2:200 
 route-target export 2:200 
 route-target import 2:200 
 mdt default 239.1.1.1 

!--- Configure the default MDT address.
 
 mdt data 238.2.2.0 0.0.0.255 threshold 1 

!--- Configure the data MDT range and threshold.
 
! 
ip multicast-routing  

!--- Enable global multicast routing.
 
ip multicast-routing vrf yellow  

!--- Enable multicast routing in VRF yellow.
 
ip cef 
mpls label protocol ldp 
tag-switching tdp router-id Loopback0 
! 
! 
! 
interface Loopback0 
 ip address 50.0.0.4 255.255.255.255 
 ip pim sparse-dense-mode 
! 
interface Loopback100 
 ip vrf forwarding yellow 
 ip address 100.0.0.4 255.255.255.255 
 ip pim sparse-dense-mode 
! 
interface Serial1/0 
 ip address 10.3.0.4 255.255.255.0 
 ip pim sparse-dense-mode 
 tag-switching ip 
! 
interface Serial2/0 
 ip vrf forwarding yellow 
 ip address 10.4.0.4 255.255.255.0 
 ip pim sparse-dense-mode 

!--- Enable the PIM toward the CE.
 
! 
router ospf 1 
 router-id 50.0.0.4 
 log-adjacency-changes 
 network 10.0.0.0 0.255.255.255 area 0 
 network 50.0.0.0 0.0.0.255 area 0 
! 
router rip 
 version 2 
 no auto-summary 
 ! 
 address-family ipv4 vrf yellow 
 version 2 
 redistribute bgp 1 
 network 10.0.0.0 
 network 100.0.0.0 
 default-metric 5 
 no auto-summary 
 exit-address-family 
! 
router bgp 1 
 no synchronization 
 no bgp default ipv4-unicast 
 bgp log-neighbor-changes 
 redistribute rip 
 neighbor 50.0.0.2 remote-as 1 
 neighbor 50.0.0.2 update-source Loopback0 
 neighbor 50.0.0.2 activate 
 no auto-summary 
 ! 
 address-family ipv4 vrf yellow 
 redistribute connected 
 redistribute rip 
 no auto-summary 
 no synchronization 
 exit-address-family 
 ! 
 address-family vpnv4 
 neighbor 50.0.0.2 activate 
 neighbor 50.0.0.2 send-community extended 
 no auto-summary 
 exit-address-family 
! 
ip classless 
no ip http server 
ip pim bidir-enable 
! 
! 
! 
! 
! 
line con 0 
 exec-timeout 0 0 
line aux 0 
line vty 0 4 
 login 
! 
end

version 12.2 
service timestamps debug datetime msec 
service timestamps log datetime msec 
no service password-encryption 
! 
hostname R5 
! 
! 
clock timezone CET 1 
ip subnet-zero 
no ip domain lookup 
! 
ip multicast-routing  

!--- Enable global multicast routing in the CE.
 
! 
! 
interface Loopback0 
 ip address 100.0.0.5 255.255.255.255 
! 
interface Serial0/0 
 ip address 10.4.0.5 255.255.255.0 
 ip pim sparse-dense-mode 
 ip igmp join-group 224.2.2.2 
! 
router rip 
 version 2 
 network 10.0.0.0 
 network 100.0.0.0 
 no auto-summary 
! 
ip classless 
no ip http server 
ip pim bidir-enable 
! 
! 
! 
! 
! 
line con 0 
 exec-timeout 0 0 
line aux 0 
line vty 0 4 
 login 
!          
end

设计提示

• MPLS VPN组播(MVPN)在VPN配置上配置。MPLS VPN网络需要经过精心设计，以首先观察MPLS VPN网络的所有建议。

• 必须为本地组播服务配置服务提供商核心。必须为PIM稀疏模式(PIM-SM)、源特定组播(PIM-SSM)或双向PIM(PIM-BIDIR)配置核心。 密集模式PIM(PIM-DM)在MVPN配置中不作为核心协议。可以在提供商的核心中配置支持的协议组合。当某些组播组由一个PIM模式处理，而某些其他组由另一个受支持的PIM模式处理时，可以执行此操作。

• 组播VRF中支持所有组播协议。即，在组播VRF中，除了PIM-SM、PIM-SSM和PIM-BIDIR外，您还可以使用MSDP和PIM-DM

• MVPN服务可以逐个VRF单独添加。即，一台PE路由器可能同时配置了支持组播的VRF和仅单播的VRF。

• 并非单个单播VRF的所有站点都必须配置为组播。有些站点（甚至MVPN PE路由器的接口）可能未启用组播。您必须确保从不计算路由以指向未启用组播的接口。否则，组播转发将中断。

• 多个VRF可以属于同一MVPN组播域。IP编址在组播域中必须唯一。当前不可能在组播域之间或全局组播路由表中泄漏路由和/或数据包。

• MVPN必须执行MDT默认配置才能工作。配置数据MDT是可选的。如果选择配置MDT，强烈建议设置数据MDT的阈值。

• 默认MDT的IP地址确定VRF属于哪个组播域。因此，可以为多个VRF使用相同的默认MDT地址。但是，它们将在它们之间共享组播数据包，并且必须遵守组播域的其他要求（例如唯一IP编址方案）。

• 数据MDT可能配置了不同PE路由器上相同范围的IP地址，也可能没有配置。这取决于在提供商的核心中使用的PIM模式。如果服务提供商核心使用稀疏模式PIM，则每个PE路由器必须为数据MDT组使用唯一的IP地址范围。如果服务提供商核心使用源特定组播，则所有PE路由器可能配置了每个组播域的数据MDT的相同IP地址范围。

验证

本部分所提供的信息可用于确认您的配置是否正常工作。

命令输出解释程序工具（仅限注册用户）支持某些 show 命令，使用此工具可以查看对 show 命令输出的分析。

• show ip igmp groups — 显示带有直接连接到路由器并通过互联网组管理协议(IGMP)获取的接收器的组播组。

• show ip pim mdt bgp — 显示MDT默认组的路由识别器(RD)的详细边界网关协议(BGP)通告。

• show ip pim vrf <vrf-name>mdt send — 显示路由器在指定VRF中已做出的数据MDT通告。

• show ip pim vrf <vrf-name>mdt receive — 显示路由器在指定VRF中接收的数据MDT通告。

• show ip mroute — 显示提供商核心中IP组播路由表的内容。

• show ip mroute vrf <vrf-name> — 显示客户端VRF中的组播路由表。

完成以下步骤以验证您的配置是否正常工作。

1. 检查PE是否已加入默认MDT隧道的IGMP组。

   如果在VRF配置下发出default-mdt命令后对其进行配置，则PE可能无法加入默认MDT组。配置环回后，从VRF中删除mdt命令并将其放回以解决问题。

   • 对于PE-R2，发出show ip igmp groups命令。

     IGMP Connected Group Membership
     Group Address  Interface   Uptime     Expires   Last Reporter
     224.0.1.40     Serial2/0   02:21:23   stopped   10.2.0.2
     239.1.1.1      Loopback0   02:36:59   stopped   0.0.0.0

   • 对于PE-R4，发出show ip igmp groups命令。

     IGMP Connected Group Membership 
     Group Address  Interface    Uptime    Expires   Last Reporter
     224.0.1.40     Loopback0    02:51:48  00:02:39  50.0.0.4
     239.1.1.2      Loopback0    02:51:45  stopped   0.0.0.0
     239.1.1.1      Loopback0    02:51:45  stopped   0.0.0.0
     239.2.2.0      Loopback0    01:40:03  stopped   0.0.0.0 

2. 检查为每个PE收到的BGP通告。

   注意：在本示例中，检查源自对等PE PE-R2和PE-R4的MDT。

   • 对于PE-R2，发出show ip pim mdt bgp命令。

     MDT-default group 239.1.1.1 
     rid: 50.0.0.4 next_hop: 50.0.0.4 
      
     WAVL tree nodes
     
     MDT-default: 239.1.1.1  Tunnel0     source-interface: Loopback0

   • 对于PE-R4，发出show ip pim mdt bgp命令

     MDT-default group 239.1.1.1 
     rid: 50.0.0.2 next_hop: 50.0.0.2 
      
     WAVL tree nodes
     
     MDT-default: 239.1.1.1  Tunnel0     source-interface: Loopback0 
     MDT-data   : 239.2.2.0  Tunnel0     source-interface: Loopback0 

3. 检查数据MDT。

   注意：在本示例中，检查由PE-R2和PE-R4源或加入的数据MDT。

   • 对于PE-R2，发出show ip pim vrf yellow mdt send命令。

     MDT-data send list for VRF: yellow 
       (source, group)                     MDT-data group      ref_count 
       (100.0.0.1, 224.2.2.2)              239.2.2.0           1 

   • 对于PE-R2，发出show ip pim vrf yellow mdt receive命令。

     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 MSDP Advertisement, 
            U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel 
            Y - Joined MDT-data group, y - Sending to MDT-data group
     Joined MDT-data groups for VRF: yellow 
       group: 239.2.2.0 source: 0.0.0.0 ref_count: 1 

   • 检查全局组播路由表以查找默认MDT。

     注意：请注意以下信息：

     1. PE上的传出接口列表为MVRF黄色。

     2. P路由器将组视为常规组播组。

     3. 每个PE是默认MDT的源，并且仅在PE路由器中。

     4. 新标志Z表示这是组播隧道。

   • 对于PE-R2，发出show ip mroute 239.1.1.1 命令。

     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 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 
     
     (*, 239.1.1.1), 02:37:16/stopped, RP 50.0.0.3, flags: SJCFZ 
       Incoming interface: Serial2/0, RPF nbr 10.2.0.3 
       Outgoing interface list: 
         MVRF yellow, Forward/Sparse-Dense, 02:21:26/00:00:28 
     
     (50.0.0.2, 239.1.1.1), 02:37:12/00:03:29, flags: FTZ 
       Incoming interface: Loopback0, RPF nbr 0.0.0.0 
       Outgoing interface list: 
         Serial2/0, Forward/Sparse-Dense, 02:36:09/00:02:33 
     (
     50.0.0.4, 239.1.1.1), 02:36:02/00:02:59, flags: JTZ 
       Incoming interface: Serial2/0, RPF nbr 10.2.0.3 
       Outgoing interface list: 
         MVRF yellow, Forward/Sparse-Dense, 02:21:26/00:00:28

   • 对于P-R3，发出show ip mroute 239.1.1.1 命令。

      
     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 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 
     
     (*, 239.1.1.1), 02:50:24/stopped, RP 50.0.0.3, flags: S 
       Incoming interface: Null, RPF nbr 0.0.0.0 
       Outgoing interface list: 
         Serial1/0, Forward/Sparse-Dense, 02:34:41/00:03:16 
         Serial2/0, Forward/Sparse-Dense, 02:49:24/00:02:37 
     
     (50.0.0.2, 239.1.1.1), 02:49:56/00:03:23, flags: T 
       Incoming interface: Serial1/0, RPF nbr 10.2.0.2 
       Outgoing interface list: 
         Serial2/0, Forward/Sparse-Dense, 02:49:24/00:02:37 
     
     (50.0.0.4, 239.1.1.1), 02:49:47/00:03:23, flags: T 
       Incoming interface: Serial2/0, RPF nbr 10.3.0.4 
       Outgoing interface list: 
         Serial1/0, Forward/Sparse-Dense, 02:34:41/00:03:16 

   • 对于PE-R4，发出show ip mroute 239.1.1.1 命令。

     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 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 
     
     (*, 239.1.1.1), 02:51:06/stopped, RP 50.0.0.3, flags: SJCFZ 
       Incoming interface: Serial1/0, RPF nbr 10.3.0.3 
       Outgoing interface list: 
         MVRF yellow, Forward/Sparse-Dense, 02:51:06/00:00:48 
     
     (50.0.0.2, 239.1.1.1), 02:50:06/00:02:58, flags: JTZ 
       Incoming interface: Serial1/0, RPF nbr 10.3.0.3 
       Outgoing interface list: 
         MVRF yellow, Forward/Sparse-Dense, 02:50:06/00:00:48 
     
     (50.0.0.4, 239.1.1.1), 02:51:00/00:03:10, flags: FTZ 
       Incoming interface: Loopback0, RPF nbr 0.0.0.0 
       Outgoing interface list: 
         Serial1/0, Forward/Sparse-Dense, 02:35:24/00:03:00 

4. 检查全局组播路由表以查找数据MDT。

   注意：对于PE-R2，请注意传出接口为tunnel0。

   • 对于源所在的PE-R2（VRF端），发出show ip mroute vrf yellow 224.2.2.2 命令。

     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 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 
     
     (*, 224.2.2.2), 2d01h/stopped, RP 100.0.0.2, flags: S 
       Incoming interface: Null, RPF nbr 0.0.0.0 
       Outgoing interface list: 
         Tunnel0, Forward/Sparse-Dense, 2d01h/00:02:34 
     
     (100.0.0.1, 224.2.2.2), 00:05:32/00:03:26, flags: Ty 
       Incoming interface: Serial1/0, RPF nbr 10.1.0.1 
       Outgoing interface list: 
         Tunnel0, Forward/Sparse-Dense, 00:05:37/00:02:34

   • 对于源所在的PE-R2（全局组播路由），发出show ip mroute 239.2.2.0 命令。

     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 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 
     
     (*, 239.2.2.0), 02:13:27/stopped, RP 50.0.0.3, flags: SJPFZ 
       Incoming interface: Serial2/0, RPF nbr 10.2.0.3 
       Outgoing interface list: Null 
     
     (50.0.0.2, 239.2.2.0), 02:13:27/00:03:22, flags: FTZ 
       Incoming interface: Loopback0, RPF nbr 0.0.0.0 
       Outgoing interface list: 
         Serial2/0, Forward/Sparse-Dense, 02:13:27/00:03:26

   注意：只有与其连接组播源的PE路由器显示为数据MDT组地址的组播流量源。

故障排除

• 发出show ip pim vrf neighbor命令，检查PE路由器是否通过动态隧道接口建立了PIM邻居关系。如果它们已执行，则默认MDT可正常运行。

• 如果默认MDT不起作用，请发出show ip pim mdt bgp命令，检查本地路由器是否知道参与MVPN的远程PE路由器的环回。如果它们不是，请验证PIM是否在用作MP BGP会话源的环回接口上启用

• 检查SP核心是否已正确配置以在PE路由器之间传送组播。为了进行测试，您可以在一个PE路由器的环回接口上配置ip igmp join-group，并执行来自另一个PE路由器的环回的组播ping。

相关信息

• MPLS VPN新功能文档
• MPLS 支持页
• IP 组播支持页
• 技术支持 - Cisco Systems