Example for Configuring PIM over GRE Tunnel
Networking Requirements
Figure 1. PIM over GRE Tunnel Configuration Example
As shown in Figure 1, multicast services are deployed in the network. Switch B does not support multicast protocols, so multicast traffic needs to be transmitted between Switch A and Switch C through a GRE tunnel.
Follow the configuration roadmap below to configure PIM over GRE tunnel.
- Run OSPF route protocol on Switch A, Switch B and Switch C for underlay communication.
- Create GRE tunnel interfaces on Switch A and Switch C to establish a GRE tunnel; Run BGP route protocol on GRE tunnel interfaces.
- Enable PIM function on the GRE tunnel interfaces to enable the transmission of multicast packets by the GRE tunnel.
Procedure
Switch A
Step1Â Â Â Â Configure VLAN interface.
admin@SwitchA# set vlans vlan-id 11 l3-interface vlan11 admin@SwitchA# set vlans vlan-id 22 l3-interface vlan22 admin@SwitchA# set interface gigabit-ethernet te-1/1/45 family ethernet-switching native-vlan-id 11 admin@SwitchA# set interface gigabit-ethernet te-1/1/13 family ethernet-switching native-vlan-id 22 admin@SwitchA# set l3-interface loopback lo address 100.100.100.100 prefix-length 32 admin@SwitchA# set l3-interface vlan-interface vlan11 address 10.1.1.2 prefix-length 24 admin@SwitchA# set l3-interface vlan-interface vlan22 address 10.20.1.1 prefix-length 24
Step2    Enable IP routing.       Â
admin@SwitchA# set ip routing enable true
Step3Â Â Â Â Configure OSPF route protocol for underlay communication.
admin@SwitchA# set protocols ospf router-id 1.1.1.1 admin@SwitchA# set protocols ospf network 10.20.1.0/24 area 0 admin@SwitchA# set protocols ospf network 100.100.100.100/32 area 0
Step4Â Â Â Â Configure GRE tunnel name, IP, source IP, destination IP etc.
admin@SwitchA# set l3-interface tunnel tnl0 address 10.40.1.1 prefix-length 24 admin@SwitchA# set l3-interface tunnel tnl0 tunnel-mode gre-ip admin@SwitchA# set l3-interface tunnel tnl0 source 100.100.100.100 admin@SwitchA# set l3-interface tunnel tnl0 destination 200.200.200.200
Step5Â Â Â Â Configure BGP route protocol for the GRE tunnel.
admin@SwitchA# set protocols bgp local-as 100 admin@SwitchA# set protocols bgp ebgp-requires-policy false admin@SwitchA# set protocols bgp neighbor 10.40.1.2 remote-as 200 admin@SwitchA# set protocols bgp ipv4-unicast network 10.1.1.0/24
Step6    Enable PIM on the GRE tunnel interface, configure Switch A’s GRE tunnel interface as the static RP.
admin@SwitchA# set protocols pim interface vlan11 sm admin@SwitchA# set protocols pim interface tnl0 sm admin@SwitchA# set protocols pim rp 10.40.1.1 group 225.0.0.0/8
Step7Â Â Â Â Commit the configuration.
admin@SwitchA# commit
Switch B
Step1Â Â Â Â Configure VLAN interface.
admin@SwitchB# set vlans vlan-id 22 l3-interface vlan22 admin@SwitchB# set vlans vlan-id 33 l3-interface vlan33 admin@SwitchB# set interface gigabit-ethernet ge-1/1/3 family ethernet-switching native-vlan-id 22 admin@SwitchB# set interface gigabit-ethernet te-1/1/1 family ethernet-switching native-vlan-id 33 admin@SwitchB# set l3-interface vlan-interface vlan22 address 10.20.1.2 prefix-length 24 admin@SwitchB# set l3-interface vlan-interface vlan33 address 10.30.1.1 prefix-length 24
Step2    Enable IP routing.        Â
admin@SwitchB# set ip routing enable true
Step3Â Â Â Â Configure OSPF for the connections between Switch A, Switch B and Switch C.
admin@SwitchB# set protocols ospf router-id 2.2.2.2 admin@SwitchB# set protocols ospf network 10.30.1.0/24 area 0 admin@SwitchB# set protocols ospf network 10.20.1.0/24 area 0
Step4Â Â Â Â Commit the configuration.
admin@SwitchB# commit
Switch C
Step1Â Â Â Â Configure VLAN interface.
admin@SwitchC# set vlans vlan-id 33 l3-interface vlan33 admin@SwitchC# set vlans vlan-id 44 l3-interface vlan44 admin@SwitchC# set interface gigabit-ethernet te-1/1/17 family ethernet-switching native-vlan-id 33 admin@SwitchC# set interface gigabit-ethernet te-1/1/23 family ethernet-switching native-vlan-id 44 admin@SwitchC# set l3-interface loopback lo address 200.200.200.200 prefix-length 32 admin@SwitchC# set l3-interface vlan-interface vlan33 address 10.30.1.2 prefix-length 24 admin@SwitchC# set l3-interface vlan-interface vlan44 address 10.2.1.2 prefix-length 24
Step2    Enable IP routing.        Â
admin@SwitchC# set ip routing enable true
Step3Â Â Â Â Configure OSPF routes for underlay communication.
admin@SwitchC# set protocols ospf router-id 3.3.3.3 admin@SwitchC# set protocols ospf network 10.30.1.0/24 area 0 admin@SwitchC# set protocols ospf network 200.200.200.200 area 0
Step4 Â Â Â Â Configure GRE tunnel name, IP, source IP, destination IP etc.
admin@SwitchC# set l3-interface tunnel tnl0 address 10.40.1.2 prefix-length 24 admin@SwitchC# set l3-interface tunnel tnl0 tunnel-mode gre-ip admin@SwitchC# set l3-interface tunnel tnl0 source 200.200.200.200 admin@SwitchC# set l3-interface tunnel tnl0 destination 100.100.100.100
Step5Â Â Â Â Configure BGP routes for the GRE tunnel.
admin@SwitchC# set protocols bgp local-as 200 admin@SwitchC# set protocols bgp ebgp-requires-policy false admin@SwitchC# set protocols bgp neighbor 10.40.1.1 remote-as 100 admin@SwitchC# set protocols bgp ipv4-unicast network 10.2.1.0/24
Step6    Enable PIM on the GRE tunnel interface, configure Switch A’s GRE tunnel interface as the static RP.
admin@SwitchC# set protocols pim interface vlan33 sm admin@SwitchC# set protocols pim interface tnl0 sm admin@SwitchC# set protocols pim rp 10.40.1.1 group 225.0.0.0/8
Step7Â Â Â Â Configure the IGMP function of the connected receiver interface.
admin@SwitchC# set protocols igmp interface vlan44
Step8Â Â Â Â Commit the configuration.
admin@SwitchC# commit
Verifying the Configuration
- After the configuration is complete, run run show pim interface to view the configuration and operation state of PIM on an interface.
admin@switchA# run show pim interface Interface State   Address  PIM Nbrs PIM DR    FHR IfChannels tnl0      up    10.40.1.1  1        10.40.1.2   0   2 pimreg    up    0.0.0.0    0        local       0   0 vlan11    up    10.1.1.2   0        local       0   0 admin@switchC# run show pim interface Interface State Address   PIM Nbrs PIM DR FHR IfChannels tnl0      up    10.40.1.2   1        local  0   0 pimreg    up    0.0.0.0     0        local  0   0  vlan44    up    10.2.1.2    0        local  0   2
- Run command run show l3-interface tunnel to display information about the GRE tunnel interface.
admin@SwitchA# run show l3-interface tunnel tnl0 tnl0       State:UP           Tunnel Source: 100.100.100.100       Tunnel Destnation: 200.200.200.200      Tunnel protocol/transport: gre-ip           Inet addr: 10.40.1.1           Traffic statistics:             5 sec input rate IPv4 1200 packets/sec, IPv6 0 packets/sec             5 sec forwarding rate IPv4 80 packets/sec, IPv6 0 packets/sec             IPv4 Input Packets............................28             IPv4 Forwarding Packets.......................5             IPv6 Input Packets............................0              IPv6 Forwarding Packets.......................0
- Run commands run show pim neighbor and run show pim rp-info to that the PIM neighbor information and RP information have been generated correctly.
admin@switchA# run show pim neighbor Interface Neighbor    Uptime   Holdtime DR Pri tnl0     10.40.1.2   03:10:40  00:01:34 1 admin@switchA# run show pim rp-info RP address  group/prefix-list OIF       I am RP Source Group-Type 10.40.1.1   225.0.0.0/8      tnl0       yes     Static  ASM
- In this example, multicast source 10.1.1.5 sends multicast information to multicast group 225.0.0.2. The multicast routing table generated by PIM protocol can be viewed through the run show mroute command, which shows that multicast traffic can be transmitted through the GRE tunnel.
admin@switchA# run show mroute IP Multicast Routing Table Flags: S - Sparse, C - Connected, P - Pruned      R - SGRpt Pruned, F - Register flag, T - SPT-bit set Source    Group     Flags  Proto Input     Output    TTL Uptime *         225.0.0.2  S     none  tnl0      none      0   --:--:-- 10.1.1.5  225.0.0.2  SFT   PIM  vlan11    pimreg    1   02:59:50                             STAR            tnl0      1 admin@switchC# run show mroute IP Multicast Routing Table Flags: S - Sparse, C - Connected, P - Pruned      R - SGRpt Pruned, F - Register flag, T - SPT-bit set Source    Group     Flags  Proto   Input     Output TTL Uptime *         225.0.0.2  SC    IGMP  tnl0      pimreg 1   03:07:44                             IGMP            vlan44 1 10.1.1.5   225.0.0.2  ST     STAR  tnl0      vlan44 1   03:07:17
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