Configuring an IPv6 Anycast Address for an Interface

Anycast addresses and unicast addresses are in the same address range. An anycast address is used to identify a group of interfaces on different nodes.

• Similar to a multicast address, an anycast address is listened to by multiple nodes. Therefore, it is only used as a destination address.
• The packets destined for an anycast address are transmitted to an interface that is in the interface group identified by the anycast address and is closest to the source node. (The distance between an interface and the source node is calculated based on the routing protocol). The packets destined for a multicast address are transmitted to a group of interfaces with the multicast address.

When the 6to4 tunnel is used for the communication between the 6to4 network and the native IPv6 network, the NetEngine 8000 F supports the configuration of an anycast address with the prefix of 2002:c058:6301/48 on the tunnel interface of the 6to4 relay route device.

Alternatively, you can configure a 6to4 address on the tunnel interface of the 6to4 relay route device. When multiple 6to4 relay route devices are configured on the network, the difference between the two methods is as follows:

• If an 6to4 address is used, you need to configure different addresses for tunnel interfaces of all devices.
• If an anycast address is used, you need to configure the same address for the tunnel interfaces of all devices. In this manner, the number of addresses is reduced. If a 6to4 relay route device fails, the 6to4 route device can send packets to another 6to4 relay route device based on the anycast address.

Before configuring an IPv6 anycast address, ensure that the system has been configured with a 6to4 tunnel whose source interface has been configured with an IPv4 anycast address on the network segment 192.168.99.0/24.