Networking Requirements
PIM-SM is widely used on large-scale networks with sparsely distributed group members. The key mechanisms of PIM-SM include neighbor discovery, DR election, RP discovery, RPT tree building, multicast source registration, SPT switchover and assertion.
The PIM Source-Specific Multicast (PIM-SSM) model provides a solution for source-specific multicast. It maintains the relationship between the host and the router through IGMPv3 and uses part of the PIM-SM mode technology in practical deployment of the PIM-SSM model.
Since the receiver has already known the location of the multicast source in PIM-SSM mode, there is no need for an RP in the SSM model, no need to build an RPT tree, and the multicast source registration process is not required. The PIM-SSM model uses three working mechanisms: PM-SM neighbor discovery, DR election and SPT tree building to implement multicast forwarding tasks in the PIM domain.
In the following topology, a multicast Source sends the multicast traffic to the Receiver through Switch A, Switch B and Switch C.
- Configure ge-1/1/2 as an IGMPv3 interface on Switch A which connects to the Receiver.
- In this example, the static route in the RIB will be used by PIM-SSM.
- Enable IGMPv3 on the L3 VLAN interfaces of the PIM router connected to the receiver.
- No need for RP configurations in PIM-SSM.
Figure 1. PIM-SSM Multicast Routing Configuration
Procedure
Switch A
Step1 Configure VLAN.
admin@XorPlus# set vlans vlan-id 2 l3-interface vlan-2 admin@XorPlus# set vlans vlan-id 3 l3-interface vlan-3 admin@XorPlus# set interface gigabit-ethernet ge-1/1/1 family ethernet-switching native-vlan-id 2 admin@XorPlus# set interface gigabit-ethernet ge-1/1/2 family ethernet-switching native-vlan-id 3 admin@XorPlus# set l3-interface vlan-interface vlan-2 address 10.10.1.1 prefix-length 24 admin@XorPlus# set l3-interface vlan-interface vlan-3 address 10.10.3.1 prefix-length 24
Step2 Enable IP routing.
admin@Xorplus# set ip routing enable true
Step3 Enable IGMPv3 on the L3 VLAN interfaces of the PIM router connected to the receiver.
admin@XorPlus# set protocols igmp interface vlan-3 version 3
Step4 Enable PIM-SM on the L3 VLAN interfaces.
admin@XorPlus# set protocols pim interface vlan-2 sm admin@XorPlus# set protocols pim interface vlan-3 sm
Step5 Configure static routes to other switches.
admin@XorPlus#set protocols static route 10.10.2.0/24 next-hop 10.10.1.2 admin@XorPlus#set protocols static route 10.10.4.0/24 next-hop 10.10.1.2
Step6 Commit the configuration.
admin@Xorplus# commit
Step7 Verify the configuration.
- Run run show pim interface command to show information about all interfaces on which PIM-SM is enabled.
admin@XorPlus# run show pim interface Interface State Address PIM Nbrs PIM DR FHR IfChannels vlan-2 up 10.10.1.1 0 local 0 0 vlan-3 up 10.10.3.1 0 local 0 0
- Run run show igmp interface command to show IGMP interface information.
admin@XorPlus# run show igmp interface Interface State Address V Querier Query Timer Uptime vlan-2 up 10.10.1.1 3 local 00:00:40 02:13:12 vlan-3 mtrc 10.10.3.1 3 other --:--:-- 00:36:29
Switch B
Step1 Configure VLAN.
admin@XorPlus# set vlans vlan-id 2 l3-interface vlan-2 admin@XorPlus# set vlans vlan-id 3 l3-interface vlan-3 admin@XorPlus# set interface gigabit-ethernet ge-1/1/1 family ethernet-switching native-vlan-id 2 admin@XorPlus# set interface gigabit-ethernet ge-1/1/2 family ethernet-switching native-vlan-id 3 admin@XorPlus# set l3-interface vlan-interface vlan-2 address 10.10.1.2 prefix-length 24 admin@XorPlus# set l3-interface vlan-interface vlan-3 address 10.10.2.2 prefix-length 24
Step2 Enable IP routing.
admin@Xorplus# set ip routing enable true
Step3 Enable PIM-SM on the L3 VLAN interfaces.
admin@XorPlus# set protocols pim interface vlan-2 sm admin@XorPlus# set protocols pim interface vlan-3 sm
Step4 Configure static routes to other switches.
admin@XorPlus#set protocols static route 10.10.3.0/24 next-hop 10.10.1.1 admin@XorPlus#set protocols static route 10.10.4.0/24 next-hop 10.10.2.1
Step5 Commit the configuration.
admin@Xorplus# commit
Step6 Verify the configuration.
- Run run show pim interface command to show information about all interfaces on which PIM-SM is enabled.
admin@XorPlus# run show pim interface Interface State Address PIM Nbrs PIM DR FHR IfChannels vlan-2 up 10.10.1.2 0 local 0 0 vlan-3 up 10.10.2.2 0 local 0 0
- Run run show igmp interface command to show IGMP interface information.
admin@XorPlus# run show igmp interface Interface State Address V Querier Query Timer Uptime vlan-2 up 10.10.1.2 2 local 00:00:40 02:13:12 vlan-3 mtrc 10.10.2.2 2 other --:--:-- 00:36:29
Switch C
Step1 Configure VLAN.
admin@XorPlus# set vlans vlan-id 2 l3-interface vlan-2 admin@XorPlus# set vlans vlan-id 3 l3-interface vlan-3 admin@XorPlus# set interface gigabit-ethernet ge-1/1/1 family ethernet-switching native-vlan-id 2 admin@XorPlus# set interface gigabit-ethernet ge-1/1/2 family ethernet-switching native-vlan-id 3 admin@XorPlus# set l3-interface vlan-interface vlan-2 address 10.10.2.1 prefix-length 24 admin@XorPlus# set l3-interface vlan-interface vlan-3 address 10.10.4.1 prefix-length 24
Step2 Enable IP routing.
admin@Xorplus# set ip routing enable true
Step3 Enable PIM-SM on the L3 VLAN interfaces.
admin@XorPlus# set protocols pim interface vlan-2 sm admin@XorPlus# set protocols pim interface vlan-3 sm
Step4 Configure static routes to other switches.
admin@XorPlus#set protocols static route 10.10.1.0/24 next-hop 10.10.2.2 admin@XorPlus#set protocols static route 10.10.3.0/24 next-hop 10.10.2.2
Step5 Commit the configuration.
admin@Xorplus# commit
Step6 Verify the configuration.
- Run run show pim interface command to show information about all interfaces on which PIM-SM is enabled.
admin@XorPlus# run show pim interface Interface State Address PIM Nbrs PIM DR FHR IfChannels vlan-2 up 10.10.2.1 0 local 0 0 vlan-3 up 10.10.4.1 0 local 0 0