Register Packets - HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual

For example, Router A has an entry for (*, 239.255.1.1) with incoming interface
PPP 1, outgoing interface Ethernet 0/2, and RP 192.168.1.1. Router A periodi-
cally sends a join/prune packet on PPP 1 which contains an entry for multicast
group 239.255.1.1. This entry's join list contains 192.168.1.1, marked with a
wildcard bit, for the source address.

Register Packets

Register packets encapsulate multicast traffic. The DR sends the register
packet to the RP for the traffic's group to register with the RP and inform the
RP of the presence and location of the source.
When a DR receives traffic from a multicast source, it looks up the RP
configured to support that group. The DR then encapsulates the multicast
packets in register packets and unicasts them to the RP.
The RP decapsulates the packets and forwards them as multicasts along the
RP tree.
As soon as a source registers with the RP, the RP sends a join for an SP tree
towards the source in order to draw the multicast traffic towards itself and
the RP tree. Figure 11-9 illustrates the flow of multicast and register packets
when a multicast source initially begins transmitting.
Multicast
Destination:
239.255.1.1
4.4.4.4
Router D
Multicast
Destination:
Group: 239.255.1.1
239.255.1.1
Figure 11-9. Sending Register Packets
Configuring Multicast Support with PIM-SM
Register
Destination:
1.1.1.1
1.1.1.1
Router A
RP
2.2.2.2
Router B Group: 239.255.1.1
Overview
Multicast
Destination:
239.255.1.1
3.3.3.3
Router C
DR
Multicast
Source
11-25