WB1 8.9 Multicast Tunneling

8.9 Multicast Tunneling

• Without configuring multicast routing on the transit nodes, make sure that receivers on SW3 may receive multicast feeds from R1.
• Do not configure any additional IGP adjacencies to accomplish this task.

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R1:
interface Tunnel 0
ip unnumbered Loopback0
tunnel source Loopback0
tunnel destination 150.1.9.9
ip pim sparse-dense-mode
!
router ospf 1
passive-interface Tunnel0

SW3:
ip multicast-routing
!
interface Tunnel 0
ip unnumbered Loopback0
tunnel source Loopback0
tunnel destination 150.1.1.1
ip pim sparse-dense-mode
!
router ospf 1
passive-interface Tunnel0
!
ip mroute 0.0.0.0 0.0.0.0 tunnel 0
!
ip access-list standard SPARSE_GROUPS
permit 224.0.0.0 0.255.255.255
!
ip pim rp-address 150.1.5.5 SPARSE_GROUPS

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To verify your configuration, Join SW3’s interface VLAN 9 to the multicast group
224.10.10.10 and ping this group from R1. Note that enabling PIM on the
interface is mandatory, as otherwise IOS will not forward multicasts out of this
interface.

SW3:
interface Vlan 9
ip igmp join-group 224.10.10.10
ip pim sparse-dense-mode

Notice that all RPF information on SW3 is condensed into one single default
mroute. It overrides all checks using the unicast routing table and allows SW3 to
receive multicasts successfully.