IPv6 Multicast Versus Anycast Address Behavior

200-301 By islever Editorial Last updated

Describe IPv6 address types

Short answer

B A multicast packet reaches one or more group members at once, while an anycast packet is routed to the closest interface sharing that anycast address.

Question

What is a difference between an IPv6 multicast address and an IPv6 anycast address?
  1. An IPv6 multicast address uses the prefix 2002::/15 and forwards to one destination, and an IPv6 anycast address uses the prefix ff00:/8 and forwards to any destination in a group.
  2. A packet sent to an IPv6 multicast address is delivered to one or more destinations at once, but a packet sent to an IPv6 anycast address is routed to the closest interface with that address. Correct Answer
  3. IPV6 multicast addresses are used to transition from IPv4 to IPv6, and IPv6 anycast addresses are used for address aggregation in an IPv6-only environment.
  4. An IPV6 multicast address is assigned to numerous interfaces within a subnet, but an IPv6 anycast address is used for a predefined group of nodes in an all-IPv6 routers group.

Key Takeaways

The defining contrast: multicast = many receivers at once; anycast = one nearest receiver among several with the same address.

IPv6 multicast (ff00::/8) delivers to all interfaces in a group simultaneously. Anycast is assigned to multiple interfaces but a packet is routed to the topologically nearest one, useful for services like DNS resolvers.

Common mistake: Trusting the prefix wording in A/D. Anycast has no special prefix (it uses normal unicast space); the behavior (closest interface) is what distinguishes it, not an address range.

Expert Analysis

Why the Answer Is Correct

B is correct. Multicast delivers a packet to one or more group members simultaneously, whereas anycast routes the packet to the nearest (topologically closest) interface among those sharing the anycast address.

Why the Other Options Are Wrong

A is wrong: the prefixes are swapped/nonsensical (multicast is ff00::/8, anycast has no dedicated prefix). C is wrong: that describes 6to4 transition, not the multicast/anycast difference. D is wrong: it actually describes an all-routers multicast group, not anycast.

Community Comment Notes

The vote is B (100). Commenters explain multicast goes to the group while anycast goes to the closest instance, noting D's second clause really describes FF02::2 all-routers multicast.

Official Reference

https://learningnetwork.cisco.com/s/ccna-exam-topics

This link opens the official vendor documentation in a new tab.

Community Votes

B
100%

100% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

  1. KAM2023 👍 3 Answered B
    In IPv6, a multicast address is used to deliver packets to multiple nodes in a group, whereas an anycast address is used to route a packet to the nearest (or best) interface among a group of interfaces that share the same anycast address. Anycast is typically used for services where the closest instance can respond to a request, providing a form of load balancing and redundancy.
  2. lmmujsi 👍 1 Answered B
    B. A packet sent to an IPv6 multicast address is delivered to one or more destinations at once, but a packet sent to an IPv6 anycast address is routed to the closest interface with that address.
  3. exiledwl 👍 1 Answered B
    B) is correct D) is incorrect because the second part describing anycast is actually describing FF02::2 multicast which is an all-ipv6 routers multicast
  4. a67c04a 👍 2 Answered B
    It´s B

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