408
Value Description
0x00000010.
&
Logical operator of "and."
XOR
Logical operator of "exclusive-or."
mod
Modulo operator, which gives the remainder of an integer division.
Embedded RP
The embedded RP mechanism enables a router to resolve the RP address from an IPv6 multicast
address so that the IPv6 multicast group is mapped to an RP. This RP can take the place of the
statically configured RP or the RP dynamically calculated based on the BSR mechanism. The DR
does not need to learn the RP address beforehand. The specific process is as follows.
•
At the receiver side:
a.
A receiver host initiates an MLD report to announce that it is joining an IPv6 multicast group.
b.
After receiving the MLD report, the receiver-side DR resolves the RP address embedded in
the IPv6 multicast address and sends a join message to the RP.
•
At the IPv6 multicast source side:
c.
The IPv6 multicast source sends IPv6 multicast traffic to the IPv6 multicast group.
d.
The source-side DR resolves the RP address embedded in the IPv6 multicast address, and
sends a register message to the RP.
RPT building
Figure 120 RPT building in an IPv6 PIM-SM domain
As shown in
, the process of building an RPT is as follows:
1.
When a receiver joins IPv6 multicast group G, it uses an MLD report message to inform the
directly connected DR.
2.
After getting the IPv6 multicast group G's receiver information, the DR sends a join message,
which is forwarded hop by hop to the RP that corresponds to the multicast group.
3.
The routers along the path from the DR to the RP form an RPT branch. Each router on this
branch generates a (*, G) entry in its forwarding table. The asterisk means any IPv6 multicast
source. The RP is the root of the RPT, and the DRs are the leaves of the RPT.
Source
Server
Host A
Host B
Host C
Receiver
Receiver
IPv6 multicast packets
RPT
Join message
RP
DR
DR
