Protocols And Standards; How Md-Vpn Works; Default-Mdt Establishment - HP 6125XLG Ip Multicast Configuration Manual

PE-PE PIM neighboring relationship—Established between PE devices that are in the same VPN
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instance after they receive the PIM hello packets.
PE-CE PIM neighboring relationship—Established between a PE interface that is bound with the
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VPN instance and the peer interface on the CE device over the link.

Protocols and standards

RFC 6037, Cisco Systems' Solution for Multicast in BGP/MPLS IP VPNs

How MD-VPN works

This section describes how the MD-VPN technology is implemented, including the default-MDT
construction, multicast traffic delivery based on the default-MDT, and inter-AS MD-VPN implementation.
For a VPN instance, multicast data transmission on the public network is transparent. The VPN data is
exchanged between the MTIs of the local PE and the remote PE. This implements the seamless
transmission of the VPN data over the public network. However, the multicast data transmission process
(the MDT transmission process) over the public network is very complicated.

Default-MDT establishment

The multicast routing protocol running on the public network can be PIM-DM or PIM-SM. The process of
creating a default-MDT is different in these PIM modes.
Default-MDT establishment in a PIM-DM network
Figure 60 Default-MDT establishment in a PIM-DM network
As shown in
A. The process of establishing a default-MDT is as follows:
1. To establish PIM neighboring relationships with PE 2 and PE 3 through the MTI in VPN instance A,
PE 1 does the following:
Figure 60, PIM-DM is enabled in the network, and all the PE devices support VPN instance
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