Bgp Multicasting; Investigating Multicast Routes - Juniper JUNOSE 11.1.X MULTICAST ROUTING Configuration Manual

JUNOSe 11.1.x Multicast Routing Configuration Guide

BGP Multicasting

BGP multicasting (MBGP) is an extension of the BGP unicast routing protocol. Many
of the functions available for BGP unicasting are also available for MBGP.
The MBGP extensions specify that BGP can exchange information within different
types of address families. The address families available are unicast IPv4, multicast
IPv4, and VPN-IPv4. When you enable BGP, the router employs unicast IPv4 addresses
by default.
We recommend you be thoroughly familiar with BGP before configuring MBGP. See
Configuring BGP Routing in the JUNOSe BGP and MPLS Configuration Guide for detailed
information about BGP and MBGP.

Investigating Multicast Routes

You can use the mtrace command to trace the path that multicast packets take from
a source to a destination through a multicast group address. This command is similar
to the traceroute command for investigating unicast routes.
mtrace
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BGP Multicasting

If PIM is configured on the interface, the virtual router supplies a list of the
interface's PIM neighbors and indicates which neighbors are leaf neighbors.
Information about DVMRP and GRE tunnels:
If the interface is an endpoint of a tunnel, the virtual router specifies the IP
address of the endpoint of the tunnel.
Use to trace the path that multicast packets take to a destination.
Specify the unicast IP address of the source for the packets.
To direct the packets to a particular destination, specify the unicast address for
that destination. If you do not specify a destination, the router traces the route
from the device on which you issue the command.
To direct the packets through a particular multicast group address, specify that
multicast group address. If you do not specify a multicast group address, the
router traces the route through the MBone audio multicast group.
To send the trace to a particular device, specify the IP address of that device. If
you do not specify a response address, the router sends the trace to an IP address
on the router.
To investigate a problem at a particular point in the route, specify the maximum
number of hops for the trace. The default number of hops is 64.
The trace starts at the destination and works back to the source.
Field descriptions
Tracing multicast route from a.a.a.a to b.b.b.b for group c.c.c.c using response
address d.d.d.d A description of the trace is as follows: