HP 6125XLG Ip Multicast Configuration Manual page 187

VPN multicast data packets are forwarded across the public network differently in the following
circumstances:
If PIM-DM or PIM-SSM is running in the VPN, the multicast source forwards multicast data packets
•
to the receivers along the VPN SPT across the public network.
When PIM-SM is running in the VPN:
•
Before the RPT-to-SPT switchover, if the multicast source and the VPN RP are in different sites, the
VPN multicast data packets travel to the VPN RP along the VPN SPT across the public network.
If the VPN RP and the receivers are in different sites, the VPN RP forwards VPN multicast data
packets to the receivers along the VPN RPT over the public network.
After the RPT-to-SPT switchover, if the multicast source and the receivers are in different sites, the
VPN multicast data packets travel to the receivers along the VPN SPT across the public network.
When BIDIR-PIM is running in the VPN, if the multicast source and the VPN RP are in different sites,
•
the multicast source sends multicast data to the VPN RP across the public network along the
source-side RPT. If the VPN RP and the receivers are in different sites, the VPN multicast data travels
to the receivers across the public network along the receiver-side RPT.
For more information about RPT-to-SPT switchover, see
The following example explains how multicast data packets are delivered based on the default-MDT
when PIM-DM is running in both the public network and the VPN network.
As shown in Figure 63:
PIM-DM is running in both the public network and the VPN sites.
•
Receiver of the VPN multicast group G (225.1.1.1) in Site 2 is attached to CE 2.
•
• Source in Site 1 sends multicast data to multicast group (G).
The default-group address used to forward public network multicast data is 239.1.1.1.
•
Figure 63 Multicast data packet delivery
A VPN multicast data packet is delivered across the public network as follows:
1. Source sends a VPN multicast data packet (192.1.1.1, 225.1.1.1) to CE 1.
"Configuring
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PIM."