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.

This topic discusses the following:

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.

host1#mtrace 100.4.4.4 40.1.1.1 232.1.1.1 Tracing multicast route from 100.4.4.4 to 40.1.1.1 for group 232.1.1.1 using response address 10.6.129.56(Press ^c to stop.) Received mtrace response packet of length 88 1. 40.1.1.1 Protocol: PIM(3) FwdingCode: RPF iif(9) 2. 21.2.2.2 Protocol: PIM(3) FwdingCode: Reached RP(8)

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