HP 4800G Series Configuration Manual page 1013

Figure 1-4 BSR and C-RPs
C-RP
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Based on the information in the RP-sets, all routers in the network can calculate the location of the
corresponding RPs based on the following rules:
1) The C-RP with the highest priority wins.
2) If all the C-RPs have the same priority, their hash values are calculated through the hashing
algorithm. The C-RP with the largest hash value wins.
3) If all the C-RPs have the same priority and hash value, the C-RP has the highest IP address wins.
The hashing algorithm used for RP calculation is: Value (G, M, C
& M) + 12345) XOR C
algorithm.
Table 1-1 Values in the hashing algorithm
Value
Value Hash value
The digest from the exclusive-or (XOR) operation between the 32-bit segments
of the IPv6 multicast group address. For example, if the IPv6 multicast address is
G
FF0E:C20:1A3:63::101, G = 0xFF0E0C20 XOR 0x01A30063 XOR 0x00000000
XOR 0x00000101
M Hash mask length
The digest from the exclusive-or (XOR) operation between the 32-bit segments
of the C-RP IPv6 address. For example, if the IPv6 address of the C-RP is
C
i
3FFE:B00:C18:1::10, C
XOR 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 allows a router to resolve the RP address from an IPv6 multicast
address so that the IPv6 multicast group is mapped to an RP, which can take the place of the statically
IPv6 PIM-SM
BSR
C-RP
31
) + 12345) mod 2 . The table below gives the meanings of the values in this
i
= 0x3FFE0B00 XOR 0x0C180001 XOR 0x00000000
i
C-RP
C-BSR
) = (1103515245 * ( (1103515245 * (G
i
Description
1-8