1、网络拓扑图
2、工作机制
1）邻居发现
PIM路由器通过开启PIM的接口互发HELLO，发现邻居。HELLO报文用来建立邻居并维持邻居关系，并选举DR，目标地址为224.0.0.13，默认每30s发送一次，Hold时间为30*3.5=105s
2）扩散
将组播源发送的组播报文扩散到全网，沿途每台PIM-DM路由器创建（S,G）项
3）剪枝/加入
如下需要上游发送组播报文，则发送Prune消息共享网络上有路由器连接接收者，则该路由器发送JOIN消息来覆盖其他路由器发送的prune消息
4）嫁接
使得有新组成员加入的网段快速收到组播流量。
5）状态刷新
防止被剪枝接口计时器超时后恢复转发，造成周期性的扩散剪枝，导致网络负荷增加
6）断言
3、配置
R1:
<r1>display current-configuration
[V200R003C00]
#
sysname r1
#
snmp-agent local-engineid 800007DB03000000000000
snmp-agent
#
clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
drop illegal-mac alarm
#
multicast routing-enable
#
set cpu-usage threshold 80 restore 75
#
aaa
authentication-scheme default
authorization-scheme default
accounting-scheme default
domain default
domain default_admin
local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
local-user admin service-type http
#
firewall zone Local
priority 15
#
interface GigabitEthernet0/0/0
ip address 10.1.1.1 255.255.255.252
pim dm
#
interface GigabitEthernet0/0/1
ip address 20.1.1.1 255.255.255.252
pim dm
#
interface GigabitEthernet0/0/2
ip address 30.1.1.1 255.255.255.252
pim dm
#
interface NULL0
#
interface LoopBack0
ip address 1.1.1.1 255.255.255.255
#
ospf 100 router-id 1.1.1.1
area 0.0.0.0
network 10.1.1.0 0.0.0.3
network 20.1.1.0 0.0.0.3
network 30.1.1.0 0.0.0.3
#
pim
#
user-interface con 0
authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return
<r1>
R2:
<r2>display current-configuration
[V200R003C00]
#
sysname r2
#
snmp-agent local-engineid 800007DB03000000000000
snmp-agent
#
clock timezone China-Standard-Time minus 08:00:00
#
portal local-server load portalpage.zip
#
drop illegal-mac alarm
#
multicast routing-enable
#
set cpu-usage threshold 80 restore 75
#
aaa
authentication-scheme default
authorization-scheme default
accounting-scheme default
domain default
domain default_admin
local-user admin password cipher %$%$K8m.Nt84DZ}e#<0`8bmE3Uw}%$%$
local-user admin service-type http
#
firewall zone Local
priority 15
#
interface GigabitEthernet0/0/0
ip address 20.1.1.2 255.255.255.252
pim dm
#
interface GigabitEthernet0/0/1
ip address 40.1.1.1 255.255.255.0
igmp enable
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
ip address 2.2.2.2 255.255.255.255
#
ospf 100 router-id 2.2.2.2
area 0.0.0.0
network 20.1.1.0 0.0.0.3
network 40.1.1.0 0.0.0.255
#
pim
#
user-interface con 0
authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return
<r2>
