IPv6 Multicast Address Blocks

IPv6 Multicast Address Blocks


Which IPv6 address block sends packets to a group address rather than a single address?



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A. B. C. D.


FF00::/8 is used for IPv6 multicast and this is the IPv6 type of address the question wants to ask.

FE80::/10 range is used for link-local addresses. Link-local addresses only used for communications within the local subnetwork (automatic address configuration, neighbor discovery, router discovery, and by many routing protocols). It is only valid on the current subnet. It is usually created dynamically using a link-local prefix of FE80::/10 and a 64-bit interface identifier (based on 48-bit MAC address).

The answer is D. FF00::/8.

IPv6 multicast addresses start with the prefix FF00::/8. Multicast addresses are used to send packets to a group of devices instead of a single device. Multicast packets are delivered to all devices in the multicast group that have expressed an interest in receiving them.

The FF00::/8 address block is reserved for multicast addresses in IPv6. The first 8 bits (11111111) are fixed, which means that the first digit of any multicast address starts with binary 1111. The remaining 4 bits (0000) are reserved for future use.

The last 112 bits are used to define the multicast group address. The last 32 bits of this address define the multicast group ID. These multicast group IDs are assigned by the Internet Assigned Numbers Authority (IANA).

Multicast addresses can be used for a variety of purposes, such as for routing protocol updates, multimedia streaming, and network time synchronization. To send a packet to a multicast address, the packet must be addressed to the multicast address, and the source device must join the multicast group by sending a special message called an IGMP (Internet Group Management Protocol) join message.

In summary, the IPv6 address block that sends packets to a group address rather than a single address is FF00::/8, which is reserved for multicast addresses in IPv6.