9.4 PIM-DM

1. 实验目的

1. 熟悉PIM-DM的应用场景
2. 掌握PIM-DM的配置方法

1. 实验拓扑

实验拓扑如图9-28所示：

                                 图9-28：PIM-DM

1. 实验步骤

（1）IP地址的配置

MCS1的配置如图9-29所示：

                                                      图9-29：配置MCS1的IP地址

R1的配置

<Huawei>system-view

Enter system view, return user view with Ctrl+Z.

[Huawei]undo info-center enable

[Huawei]sysname R1

[R1]interface g0/0/0

[R1-GigabitEthernet0/0/0]ip address 192.168.1.1 24

[R1-GigabitEthernet0/0/0]quit

[R1]interface g0/0/1

[R1-GigabitEthernet0/0/1]ip address 12.1.1.1 24

[R1-GigabitEthernet0/0/1]quit

[R1]interface g0/0/2

[R1-GigabitEthernet0/0/2]ip address 13.1.1.1 24

[R1-GigabitEthernet0/0/2]quit

R2的配置

[Huawei]sysname R2

[R2]interface g0/0/2

[R2-GigabitEthernet0/0/2]ip address 12.1.1.2 24

[R2-GigabitEthernet0/0/2]quit

[R2]interface g0/0/0

[R2-GigabitEthernet0/0/0]ip address 100.1.1.2 24

[R2-GigabitEthernet0/0/0]quit

R3的配置

<Huawei>system-view

Enter system view, return user view with Ctrl+Z.

[Huawei]undo info-center enable

Info: Information center is disabled.

[Huawei]sysname R3

[R3]interface g0/0/3

[R3-GigabitEthernet0/0/3]ip address 13.1.1.3 24

[R3-GigabitEthernet0/0/3]quit

[R3]interface g0/0/0

[R3-GigabitEthernet0/0/0]ip address 100.1.1.3 24

[R3-GigabitEthernet0/0/0]quit

R4的配置

<Huawei>system-view

Enter system view, return user view with Ctrl+Z.

[Huawei]undo info-center enable

Info: Information center is disabled.

[Huawei]sysname R4

[R4]interface g0/0/0

[R4-GigabitEthernet0/0/0]ip address 100.1.1.4 24

[R4-GigabitEthernet0/0/0]quit

[R4]interface g0/0/1

[R4-GigabitEthernet0/0/1]ip address 10.1.1.4 24

[R4-GigabitEthernet0/0/1]quit

PC1的配置

配置PC1的IP地址如图9-30所示：

                                              图9-30：配置PC1的IP地址

（2）配置IGP

R1的配置

[R1]ospf router-id 1.1.1.1

[R1-ospf-1]area 0

[R1-ospf-1-area-0.0.0.0]network 192.168.1.0 0.0.0.255

[R1-ospf-1-area-0.0.0.0]network 12.1.1.0 0.0.0.255

[R1-ospf-1-area-0.0.0.0]network 13.1.1.0 0.0.0.255

[R1-ospf-1-area-0.0.0.0]quit

R2的配置

[R2]ospf router-id 2.2.2.2

[R2-ospf-1]area 0

[R2-ospf-1-area-0.0.0.0]network 12.1.1.0 0.0.0.255

[R2-ospf-1-area-0.0.0.0]network 100.1.1.0 0.0.0.255

[R2-ospf-1-area-0.0.0.0]quit

R3的配置

[R3]ospf router-id 3.3.3.3

[R3-ospf-1]area 0

[R3-ospf-1-area-0.0.0.0]network 13.1.1.0 0.0.0.255

[R3-ospf-1-area-0.0.0.0]network 100.1.1.0 0.0.0.255

[R3-ospf-1-area-0.0.0.0]quit

R4的配置

[R4]ospf router-id 4.4.4.4

[R4-ospf-1]area 0

[R4-ospf-1-area-0.0.0.0]network 100.1.1.0 0.0.0.255

[R4-ospf-1-area-0.0.0.0]network 10.1.1.0 0.0.0.255

[R4-ospf-1-area-0.0.0.0]quit

（3）配置PIM

R1的配置

[R1]multicast routing-enable

[R1]interface g0/0/0

[R1-GigabitEthernet0/0/0]pim dm

[R1-GigabitEthernet0/0/0]quit

[R1]interface g0/0/1

[R1-GigabitEthernet0/0/1]pim dm

[R1-GigabitEthernet0/0/1]quit

[R1]interface g0/0/2

[R1-GigabitEthernet0/0/2]pim dm

[R1-GigabitEthernet0/0/2]quit

R2的配置

[R2]multicast routing-enable

[R2]interface g0/0/2

[R2-GigabitEthernet0/0/2]pim dm

[R2-GigabitEthernet0/0/2]quit

[R2]interface g0/0/0

[R2-GigabitEthernet0/0/0]pim dm

[R2-GigabitEthernet0/0/0]quit

R3的配置

[R3]multicast routing-enable

[R3]interface g0/0/3

[R3-GigabitEthernet0/0/3]pim dm

[R3-GigabitEthernet0/0/3]quit

[R3]interface g0/0/0

[R3-GigabitEthernet0/0/0]pim dm

[R3-GigabitEthernet0/0/0]quit

R4的配置

[R4]multicast routing-enable

[R4]interface g0/0/0

[R4-GigabitEthernet0/0/0]pim dm

[R4-GigabitEthernet0/0/0]quit

[R4]interface g0/0/1

[R4-GigabitEthernet0/0/1]pim dm

[R4-GigabitEthernet0/0/1]quit

（4）开启IGMP

[R4]interface g0/0/1

[R4-GigabitEthernet0/0/1]igmp  enable

[R4-GigabitEthernet0/0/1]igmp version 2

[R4-GigabitEthernet0/0/1]quit

（5）设置组播服务器

MCS1的配置如图9-31所示：

                                                  图9-31：配置组播服务器

（6）设置组播组成员

PC1的配置如图9-32所示：

                                                图9-32：配置PC1让其加入组239.1.1.1

1. 实验调试

（1）在R1上查看PIM的邻居关系

<R1>display pim  neighbor

 VPN-Instance: public net

 Total Number of Neighbors = 2

 Neighbor        Interface           Uptime   Expires  Dr-Priority  BFD-Session

 12.1.1.2        GE0/0/1             00:10:18 00:01:27 1            N         

 13.1.1.3        GE0/0/2             00:09:35 00:01:40 1            N         

【技术要点】

• Neighbor：邻居的接口IP地址
• Interface：我的哪个接口和邻居相连
• Uptime：邻居建立的时间
• Expires：失效时间，每隔30s发送一次hello包文，失效时间为105s，
• Dr-Priority：DR的优选级，默认为1。范围是0-4294967295
• BFD-Session：没有双向转发检测会话

（2）查看每一台路由器的组播路由表

查看R1的组播路由表

<R1>display multicast routing-table

Multicast routing table of VPN-Instance: public net

 Total 1 entry

 00001. (192.168.1.2, 239.1.1.1)

       Uptime: 00:00:21

       Upstream Interface: GigabitEthernet0/0/0   //上游接口

       List of 1 downstream interface

           1:  GigabitEthernet0/0/2  //下游接口

查看R2的组播路由表

<R2>display multicast routing-table

Multicast routing table of VPN-Instance: public net

 Total 1 entry

 00001. (192.168.1.2, 239.1.1.1)

       Uptime: 00:00:24

       Upstream Interface: GigabitEthernet0/0/2  //上游接口

查看R3的组播路由表

<R3>display multicast routing-table

Multicast routing table of VPN-Instance: public net

 Total 1 entry

 00001. (192.168.1.2, 239.1.1.1)

       Uptime: 00:00:29

       Upstream Interface: GigabitEthernet0/0/3  //上游接口

       List of 1 downstream interface

           1:  GigabitEthernet0/0/0  //下游接口

查看R4的组播路由表

<R4>display multicast routing-table

Multicast routing table of VPN-Instance: public net

 Total 1 entry

 00001. (192.168.1.2, 239.1.1.1)

       Uptime: 00:00:38

       Upstream Interface: GigabitEthernet0/0/0  //上游接口

       List of 1 downstream interface

           1:  GigabitEthernet0/0/1  //下游接口

通过以上输出可以得到组播流量的走向，其走向如图9-33所示：

                                            图9-33：组播流量走向图

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【技术要点】

R4会收到R2和R3发送过来的组播流量，于是会产生assert机制，选举原则为：

• 单播路由协议优先级较高者获胜。
• 如果优先级相同，则到组播源的开销较小者获胜。
• 如果以上都相同，则下游接口IP地址最大者获胜。

它们都为OSPF路由协议，所以优选级都为10，组播源的开销都为2，R2的g0/0/0接口地址为100.1.1.2，R3的g0/0/0接口为100.1.1.3，所以R3成为了winner

查看R2的组播路由表

[R2]display pim  routing-table fsm 

 VPN-Instance: public net

 Total 0 (*, G) entry; 1 (S, G) entry

 Abbreviations for FSM states and Timers:

     NI - no info, J - joined, NJ - not joined, P - pruned,

     NP - not pruned, PP - prune pending, W - winner, L - loser,

     F - forwarding, AP - ack pending, DR - designated router,

     NDR - non-designated router, RCVR - downstream receivers,

     PPT - prunepending timer, GRT - graft retry timer,

     OT - override timer, PLT - prune limit timer,

     ET - join expiry timer, JT - join timer,

     AT - assert timer, PT - prune timer

 (192.168.1.2, 239.1.1.1)

     Protocol: pim-dm, Flag: ACT

     UpTime: 00:01:00

     Upstream interface: GigabitEthernet0/0/2

         Upstream neighbor: 12.1.1.1

         RPF prime neighbor: 12.1.1.1

         Join/Prune FSM: [P, PLT Expires: 00:03:04]

     Downstream interface(s) information: None

     FSM information for non-downstream interfaces:

         1: GigabitEthernet0/0/2

             Protocol: pim-dm

             DR state: [DR]

             Join/Prune FSM: [NI]

             Assert FSM: [L, AT Expires: 00:02:34]

                 Winner: 12.1.1.1, Pref: 0, Metric: 0

         2: GigabitEthernet0/0/0

             Protocol: pim-dm

             DR state: [NDR]

             Join/Prune FSM: [NI]

             Assert FSM: [L, AT Expires: 00:02:34]  // 本路由器为loser 定时器180s，还有154s

                 Winner: 100.1.1.3, Pref: 10, Metric: 2  //winner是100.1.1.3 它的优选级为10，开销为2

（3）在R1的g0/0/1口抓包分析

第一个包hello包，其包文格式如图9-34所示：

                                                              图9-34：hello的包文格式

【技术要点】

• Hello包发往组播地址224.0.0.13
• 组播的版本为2
• 包的类型为hello
• 失效时间为105s，hello的间隔时间为30s
• DR的优选级为1
• 状态刷新时间为60s
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（3）开启组播源，然后在在PC1上点击加入再离开，在R4的g0/0/0抓包

第二个包join/prune包，其报文格式如图9-35所示：

                                         图9-35：join/prune包的包文格式

第三个包graft包，其报文格式如图9-36所示：

                                          图9-36：graft包的包文格式

第四个包graft-ack包，其包文格式如图9-37所示：

                                  图9-37：graft-ack包的包文格式

第五个包assert包，其包文格式如图9-38所示：

                                         图9-38：assert包的包文格式

第六个包stata-refresh包，其包文格式如图9-39所示：

                                             图9-39：stata-refresh包的包文格式