適用於MPLS VPN的多點傳送支援組態範例

簡介

本文提供為多重協定標籤交換(MPLS)VPN設定多點傳送支援的範例設定和一般准則。此功能是在Cisco IOS^®軟體版本12.0(23)S和12.2(13)T中匯入。

必要條件

需求

嘗試此設定之前，請確保符合以下要求：

• 服務提供商必須具有支援組播的核心才能使用思科組播VPN功能。

採用元件

本檔案中的資訊是根據Cisco IOS軟體版本12.2(13)T

注意：要獲取有關此功能的平台支援的更新資訊，請使用Software Advisor(僅限註冊客戶)。 在為功能新增新的平台支援時，軟體顧問會動態更新支援的平台清單。

本文中的資訊是根據特定實驗室環境內的裝置所建立。文中使用到的所有裝置皆從已清除（預設）的組態來啟動。如果您的網路正在作用，請確保您已瞭解任何指令可能造成的影響。

慣例

如需文件慣例的詳細資訊，請參閱思科技術提示慣例。

背景資訊

如需背景資訊，請參閱Cisco IOS軟體版本12.2(13)T的新功能檔案，以瞭解適用於MPLS VPN的IP多點傳送支援。

設定

本節提供用於設定本文件中所述功能的資訊。

網路圖表

本檔案會使用下圖中所示的網路設定。

組態

網路圖表代表服務供應商的主幹。這包括路由器R2、R3和R4。主幹配置為支援MPLS VPN。R2和R4是提供商邊緣(PE)路由器，而R3是提供商(P)路由器。R1和R5代表屬於同一VPN路由和轉發(VRF)例項的客戶邊緣(CE)路由器，顯示為黃色。

為了提供組播服務，必須將骨幹網配置為運行組播路由。為此目的選擇的組播協定是協定無關組播(PIM),R3配置為集結點(RP)。R2和R4還配置為將組播路由運行到VRF黃色。PIM稀疏 — 密集模式被配置為PE和CE之間的組播路由協定。R2已配置為VRF黃色的RP。

為了測試多點傳送連線，R5的s0/0介面設定為加入多點傳送群組224.2.2.2。Ping會從R1的回送位址傳送到224.2.2.2。網際網路控制訊息通訊協定(ICMP)回應是多點傳送封包，而ICMP回應是單點傳播封包，因為IP目的地位址是R1回送位址。

本文檔中顯示的配置包括：

• 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

設計提示

• MPLS VPN(MVPN)組播配置在VPN配置之上。需要仔細設計MPLS VPN網路，以首先遵守MPLS VPN網路的所有建議。

• 必須為本地組播服務配置服務提供商核心。核心必須配置為PIM稀疏模式(PIM-SM)、源特定組播(PIM-SSM)或雙向PIM(PIM-BIDIR)。 在MVPN配置中，不支援將密集模式PIM(PIM-DM)作為核心協定。可以在提供商核心中配置一系列受支援的協定。當一些組播組由一個PIM模式處理，而另一些組由另一個支援的PIM模式處理時，可以完成此操作。

• 組播VRF支援所有組播協定。即，在多播VRF中，除了PIM-SM、PIM-SSM和PIM-BIDIR之外，您還可以使用MSDP和PIM-DM

• 可以逐個VRF單獨新增MVPN服務。也就是說，一個PE路由器可能同時配置了支援組播的VRF和僅單播VRF。

• 並非必須將單個單播VRF的所有站點配置為進行組播。某些站點（甚至是MVPN PE路由器的介面）可能未啟用組播。必須確保路由從不會計算為指向啟用組播的介面。否則，組播轉發將中斷。

• 多個VRF可以屬於同一個MVPN組播域。IP編址在組播域內必須是唯一的。當前無法向全域性組播路由表中洩漏組播域之間的路由和/或資料包。

• MDT預設配置是MVPN工作的必備配置。配置資料MDT是可選的。如果您選擇配置資料MDT，強烈建議設定其閾值。

• 預設MDT的IP地址確定VRF屬於哪個組播域。因此，一個以上的VRF可能具有相同的預設MDT地址。但是，它們將在它們之間共用組播資料包，並且必須遵守組播域的其他要求（如唯一的IP編址方案）。

• 在不同的PE路由器上，資料MDT可能配置有相同範圍的IP地址，也可能沒有配置。這取決於提供商核心中使用的PIM模式。如果服務提供商核心使用稀疏模式PIM，則每個PE路由器必須為資料MDT組使用唯一的IP地址範圍。如果服務提供商核心使用源特定組播，則所有PE路由器可能都配置了每個組播域的資料MDT的相同範圍的IP地址。

驗證

本節提供的資訊可用於確認您的組態是否正常運作。

輸出直譯器工具(僅供註冊客戶使用)支援某些show命令，此工具可讓您檢視show命令輸出的分析。

• show ip igmp groups — 顯示具有直接連線到路由器並通過Internet組管理協定(IGMP)獲知的接收器的組播組。

• show ip pim mdt bgp — 顯示MDT預設組的路由區分器(RD)的詳細邊界網關協定(BGP)通告。

• show ip pim vrf <vrf-name> mdt send — 顯示路由器在指定VRF中進行的資料MDT通告。

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

• show ip mroute — 顯示提供商核心中IP組播路由表的內容。

• show ip mroute vrf <vrf-name> — 顯示客戶端VRF中的組播路由表。

完成以下步驟以驗證您的組態是否正常運作。

1. 檢查PE是否已加入預設MDT隧道的IGMP組。

   如果在VRF配置下發出default-mdt命令後對其進行配置，則PE可能無法加入預設MDT組。配置環回後，從VRF中刪除mdt命令並將其放回以解決問題。

   • 對於PE-R2，發出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

   • 對於PE-R4，發出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. 檢查收到的每個PE的BGP通告。

   注意：在本示例中，請檢查來自對等PE PE-R2和PE-R4的MDT。

   • 對於PE-R2，發出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

   • 對於PE-R4，發出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. 檢查資料MDT。

   注意：在本示例中，請檢查源自PE-R2和PE-R4或與之連線的資料MDT。

   • 對於PE-R2，發出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 

   • 對於PE-R2，發出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 

   • 檢查全域性組播路由表以獲取預設MDT。

     注意：請注意以下資訊：

     1. PE上的傳出介面清單為MVRF黃色。

     2. P路由器將該組視為常規組播組。

     3. 每個PE都是預設MDT的源，並且僅位於PE路由器中。

     4. 新標誌Z表示這是組播隧道。

   • 對於PE-R2，發出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

   • 對於P-R3，發出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 

   • 對於PE-R4，發出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. 檢查全域性組播路由表以查詢資料MDT。

   注意：對於PE-R2，請注意傳出介面為tunnel0。

   • 對於源所在的PE-R2（VRF端），發出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

   • 對於源所在的PE-R2（全域性組播路由），發出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：只有連線了組播源的PE路由器才會顯示為資料MDT組地址的組播流量的源。

疑難排解

• 發出show ip pim vrf neighbor命令，檢查PE路由器是否通過動態隧道介面建立了PIM鄰居關係。如果失敗，則預設MDT正常運行。

• 如果Default MDT不起作用，請發出show ip pim mdt bgp命令，檢查本地路由器是否知道參與MVPN的遠端PE路由器的環回。如果失敗，請確認在用作MP BGP作業階段來源的回送介面上啟用了PIM

• 檢查SP核心是否已正確配置為在PE路由器之間傳送組播。出於測試目的，您可以在一台PE路由器的環回介面上配置ip igmp join-group，然後執行源自另一台PE路由器環回的組播ping。

相關資訊

• MPLS VPN新功能文檔
• MPLS支援頁面
• IP多點傳送支援頁面
• 技術支援 - Cisco Systems