User Manual
UMN:CLI
V8102
545
MLD has two versions that are supported by hosts and routers. MLD messages for each
version are Query and Report types. Additionally, Done message is added to the version1.
The followings are the simple definitions of each version:
•
MLD Version 1
MLDv1 is based on IGMP2.
0 4 8 16 32
Type
Code
Checksum
Maximum Response Delay
Reserved
Multicast Address (128 bits)
Fig. 11.1
MLDv1 Message Format
MLDv1 Messages
•
Type
: MLD message types
–
General query / Multicast-address-specific query message (ICMPv6 #130)
–
Multicast Listener report message (ICMPv6 #131)
–
Multicast Listener done message (ICMPv6 #132)
•
Code
: This field is set to zero by the sender and ignored by receivers.
•
Checksum
: The standard ICMPv6 checksum, covering the entire MLD message of
IPv6 header fields.
•
Maximum Response Delay
: This field is used only in Query messages, and
specifies the maximum allowed delay before sending a responding Report, in units of
milliseconds.
•
Multicast Address
–
In a Query message
: This field is set to zero when sending a General Query, and
set to a specific IPv6 multicast address when sending a multicast-address-specific
query.
–
In a Report or Done message:
This field holds a specific IPv6 multicast address
to which the message sender is listening to is ceasing to listen, respectively.
