配置信息

R1:

<r1>display pim routing-table

VPN-Instance: public net

Total 0 (*, G) entry; 1 (S, G) entry

(10.1.1.10, 239.0.0.12)，（S,G）

    Protocol: pim-dm, Flag: LOC ACT  

    UpTime: 00:03:15

    Upstream interface: GigabitEthernet0/0/0

        Upstream neighbor: NULL

        RPF prime neighbor: NULL

    Downstream interface(s) information:

    Total number of downstreams: 1

        1: GigabitEthernet0/0/1

            Protocol: pim-dm, UpTime: 00:03:15, Expires: never

R2:

<r2>display pim routing-table

VPN-Instance: public net

Total 0 (*, G) entry; 1 (S, G) entry

(10.1.1.10, 239.0.0.12)，（S,G）

    Protocol: pim-dm, Flag: ACT  

    UpTime: 00:00:51

    Upstream interface: GigabitEthernet0/0/0

        Upstream neighbor: 20.1.1.1

        RPF prime neighbor: 20.1.1.1

    Downstream interface(s) information:

    Total number of downstreams: 1

        1: GigabitEthernet0/0/1

            Protocol: pim-dm, UpTime: 00:00:51, Expires:  - 

R3：

[r3]display pim routing-table

VPN-Instance: public net

Total 1 (*, G) entry; 1 (S, G) entry

(*, 239.0.0.12)

    Protocol: pim-dm, Flag: WC  

    UpTime: 01:11:45

    Upstream interface: NULL

        Upstream neighbor: NULL

        RPF prime neighbor: NULL

    Downstream interface(s) information:

    Total number of downstreams: 1

        1: GigabitEthernet0/0/1

            Protocol: static igmp, UpTime: 01:11:45, Expires: never

(10.1.1.10, 239.0.0.12)，（S，G）

    Protocol: pim-dm, Flag: ACT  

    UpTime: 00:03:59

    Upstream interface: GigabitEthernet0/0/0

        Upstream neighbor: 30.1.1.1

        RPF prime neighbor: 30.1.1.1

    Downstream interface(s) information:

    Total number of downstreams: 1

        1: GigabitEthernet0/0/1

            Protocol: pim-dm, UpTime: 00:03:59, Expires:  - 

RPF(RESERVER PATH FORWARDING): 10.1.1.1->20.1.1.2->30.1.1.2

单播路由：40.1.1.1->30.1.1.1->20.1.1.1->10.1.1.1.10