我使用 ISR4431 的 PIM-SSM 多播配置存在问题。我想将来自应用程序的广播数据从多播源上的一个 VLAN 转发到小型网络上多播路由器上的另一个 VLAN。我使用的方法是 PIM-SSM。我有一个多播源 R1、一个多播过渡路由器 R2 和一个多播接收器，即 R3 设备。欢迎任何关于为什么广播数据不转发的见解。

  这是拓扑和配置：

              R1—R2—R3

R1 配置（多播源）：

hostname R1
ip multicast-routing distributed
ip pim spt-threshold infinity
ip pim ssm default
no ip igmp snooping
vtp mode transparent
spanning-tree extend system-id
vlan internal allocation policy ascending
vlan 100
interface GigabitEthernet0/0/0
 ip address 10.194.234.226 255.255.255.252
 ip nat outside
 ip pim sparse-dense-mode
interface GigabitEthernet0/1/0
 switchport access vlan 100
 switchport mode access
interface Vlan100
 ip address 10.1.1.1 255.255.255.0
 ip nat inside
 ip pim sparse-dense-mode
 ip multicast helper-map broadcast 232.1.1.1 bcast-to-mcast ttl 50
ip forward-protocol udp 3205
ip nat inside source static udp 10.1.1.71 3205 10.194.234.226 3205 extendable
ip route 0.0.0.0 0.0.0.0 G0/0/0
ip access-list extended bcast-to-mcast
 permit udp any any eq 3205
end

R2 配置（组播转换路由器）：

hostname R2
ip multicast-routing distributed
ip pim spt-threshold infinity
vtp mode transparent
spanning-tree extend system-id
vlan internal allocation policy ascending
interface GigabitEthernet0/0/0
 ip address 10.194.234.225 255.255.255.252
 ip pim sparse-dense-mode
 no shutdown
 negotiation auto
interface GigabitEthernet0/0/1
 ip address 10.156.51.225 255.255.255.252
 ip pim sparse-dense-mode
 no shutdown
 negotiation auto
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0/0
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0/1
end

R3 Config（组播接收器，注意：192.142.1.99 不是接收数据的设备。vlan 600 上的其他设备需要数据）：  

hostname R3
ip multicast-routing distributed
ip pim spt-threshold infinity
ip pim ssm default
no ip igmp snooping
vtp mode transparent
spanning-tree extend system-id
vlan internal allocation policy ascending
vlan 600
interface GigabitEthernet0/0/0
 ip address 10.156.51.226 255.255.255.252
 ip pim sparse-dense-mode
 ip multicast helper-map 232.1.1.1 192.142.1.255 bcast-to-mcast
 ip igmp version 3
 negotiation auto
interface GigabitEthernet0/1/0
 switchport access vlan 600
 switchport mode access
interface GigabitEthernet0/1/1
switchport access vlan 600
switchport mode access
interface Vlan600
 ip address 192.142.1.1 255.255.255.0
 ip broadcast-address 192.142.1.255
 ip directed-broadcast
 ip pim sparse-dense-mode
 ip igmp join-group 232.1.1.1 source 10.194.234.226
 ip igmp version 3
ip forward-protocol udp 3205
ip nat inside source static tcp 192.142.1.99 61000 10.156.51.226 61000 extendable
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0/0
ip access-list extended bcast-to-mcast
 permit udp any any eq 3205
end