IPv6 Anycast Address Characteristics

EF

A new address type made specifically for IPv6 is called the Anycast Address. These IPv6 addresses are global addresses, these addresses can be assigned to more than one interface unlike an IPv6 unicast address. Anycast is designed to send a packet to the nearest interface that is a part of that anycast group.

The sender creates a packet and forwards the packet to the anycast address as the destination address which goes to the nearest router. The nearest router or interface is found by using the metric of a routing protocol currently running on the network. However, in a LAN setting the nearest interface is found depending on the order the neighbors were learned. The anycast packet in a LAN setting forwards the packet to the neighbor it learned about first.

An anycast address is an IPv6 address that is assigned to a group of devices, but only one device in the group can receive packets that are sent to the anycast address. An anycast address allows a device to send a packet to the closest device in the group. An anycast address is different from a multicast address, which allows a packet to be sent to multiple devices in a group.

The characteristics of an IPv6 anycast address are:

B. One-to-nearest communication model: When a packet is sent to an anycast address, it is delivered to the device in the group that is closest to the sending device. This means that anycast addresses can be used to provide a service that is available from multiple locations, but the closest location to the client will respond to the request.

E. The same address for multiple devices in the group: An anycast address is assigned to a group of devices, but only one device can receive packets sent to the address. This means that multiple devices in the group can have the same anycast address.

F. Delivery of packets to the group interface that is closest to the sending device: Anycast addresses are used to send packets to the closest device in a group. This is accomplished by advertising the anycast address with the same prefix on multiple interfaces, and the closest interface will respond to the request.

Therefore, the correct answers are B, E, and F.

A is incorrect because anycast is a one-to-nearest communication model, not a one-to-many communication model.

C is incorrect because any-to-many communication is a characteristic of multicast, not anycast.

D is incorrect because each device in an anycast group can have the same anycast address.