3Com S7906E - Switch, Configuration Manual

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1-6
Figure 1-3 Format of MLDv2 query message
Multicast Address (128 bits)
Type = 130 Code
0 7 15 31
Checksum
Maximum Response Delay Reserved
Reserved S QRV QQIC Number of Sources (n)
...
3 4
Source Address [1] (128 bits)
Source Address [n] (128 bits)
Table 1-1 describes the fields in Figure 1-3 .
Table 1-1 Description on fields in an MLDv2 query message
Field Description
Type = 130 Message type. For a query message, this field is set to 130.
Code Initialized to zero
Checksum Standard IPv6 checksum
Maximum Response Delay
Maximum response delay allowed before a host sends a report
message
Reserved Reserved field and initialized to zero
Multicast Address
z
This field is set to 0 in a general query message.
z
It is set to a specific IPv6 multicast address in a
multicast-address-specific query message or
multicast-address-and-source-specific query message.
S
Flag indicating whether a router updates the timer for suppression
after receiving a query message.
QRV Querier’s Robustness Variable
QQIC Querier’s Query Interval Code
Number of Sources
z
This field is set to 0 in a general query message or a
multicast-address-specific query message.
z
This field represents the number of source addresses in a
multicast-address-and-source-specific query message