IPv6 Addressing
Multicast Application to IPv6 Addressing
For information on Multicast Listener Discovery (MLD) refer to the chapter titled “Multicast Listener Discovery (MLD) Snooping”.
When MLD is enabled on an interface, you can use show ipv6 mld [ vlan < vid >] to list the active multicast group activity the switch has detected per interface from other devices.
IPv6 Multicast Address Format
The multicast address format has three principal sections in the leading 16 bits:
■identifier: ff (bits
■flags: 0xxx (bits
■scope: 0001 - 1110 (bits
For related information, refer to RFC 4291.
Multicast Group Identification
Multicast ID, Flags and Scope (16 bits) | Group Identifier (112 bits) |
1111 1111 0xxx xxxx : x...x : x...x : x...x : x...x : x...x : x...x : x...x
■multicast identifier: The first eight
■multicast flags: Bits
Bit ID | Options | Use |
9 | 0 | reserved |
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10 (R) | 0 | multicast address without |
| 1 | multicast address with |
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11 (P) | 0 | multicast address without prefix information from the |
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| originating network |
| 1 | multicast address with prefix information from the originating |
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| network |
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12 (T) | 0 | multicast address is permanent |
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| restricted by scope value) |
| 1 | multicast address is temporary (and used only within an |
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| identified scope) |
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