Multicast Traceroute - HP A5500 SI Switch Series Configuration Manual

Figure 26 Creating an RPF route
As shown in
When no multicast static route is configured, the hosts—Receivers—in the OSPF domain cannot receive
the multicast packets that the multicast source sent in the RIP domain. After you configure a multicast
static route on Router C and Router D, specifying Router B as the RPF neighbor of Router C and Router C
as the RPF neighbor of Router D, the receivers can receive multicast data that the multicast source sent.
NOTE:
A multicast static route only affects RPF check, but it cannot guide multicast forwarding. A multicast
static route is also called an "RPF static route."
A multicast static route is effective only on the multicast router on which it is configured, and will not
be advertised throughout the network or redistributed to other routers.

Multicast traceroute

You can use the multicast traceroute utility to trace the path of a multicast stream from the first-hop router
to the last-hop router.
Concepts in multicast traceroute
Last-hop router—If one of the interfaces of a router connects to the subnet that contains the given
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destination address, and if the router can forward multicast streams from the given multicast source
to that subnet, that router is called the "last-hop router."
First-hop router—The router that directly connects to the multicast source is called the "first-hop
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router."
Querier—The router that is requesting the multicast traceroute is called the "querier."
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Introduction to multicast traceroute packets
A multicast traceroute packet is a special IGMP packet that is different from common IGMP packets in
that its IGMP Type field is set to 0x1F or 0x1E and its destination IP address is a unicast address.
Multicast traceroute packets include the following types:
Figure 26, the RIP domain and the OSPF domain are unicast isolated from each other.
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