3com S7906E Instruccion De Instalación

 

1-8 

Figure 1-4 BSR and C-RPs 

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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

i

) = (1103515245 * ( (1103515245 * (G 

& M) + 12345) XOR C

i

) + 12345) mod 2

31

. The table below gives the meanings of the values in this 

algorithm.  

Table 1-1 Values in the hashing algorithm 

Value 

Hash value 

G 

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 
FF0E:C20:1A3:63::101, G = 0xFF0E0C20 XOR 0x01A30063 XOR 0x00000000 
XOR 0x00000101 

M 

Hash mask length 

C

i

 

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 
3FFE:B00:C18:1::10, C

i

 = 0x3FFE0B00 XOR 0x0C180001 XOR 0x00000000 

XOR 0x00000010 

& 

Logical operator of “and” 

XOR 

Logical operator of “exclusive-or” 

mod 

Modulo operator, which gives the remainder of an integer division 

 

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