User Manual UMN:CLIV8102545MLD has two versions that are supported by hosts and routers. MLD messages for eachversion are Query and Report types. Additionally, Done message is added to the version1.The followings are the simple definitions of each version:• MLD Version 1MLDv1 is based on IGMP2.0 4 8 16 32Type Code ChecksumMaximum Response Delay ReservedMulticast Address (128 bits)Fig. 11.1 MLDv1 Message FormatMLDv1 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 ofIPv6 header fields.• Maximum Response Delay: This field is used only in Query messages, andspecifies the maximum allowed delay before sending a responding Report, in units ofmilliseconds.• Multicast Address– In a Query message: This field is set to zero when sending a General Query, andset to a specific IPv6 multicast address when sending a multicast-address-specificquery.– In a Report or Done message: This field holds a specific IPv6 multicast addressto which the message sender is listening to is ceasing to listen, respectively.
