Configuring IPv6 with Cisco IOS provides complete coverage of IPv6 strategies, configuration scenarios, and techniques to successfully deploy an IPv6 addressing and subnetting scheme on a network. The book also covers such topics as: increasing the IP address size from 32 bits to 128 bits; supporting more levels of addressing hierarchy; supporting an increased number of addressable nodes; supporting simpler autoconfiguration of addresses; improving the scalability of multicast routing by adding a "scope" field to multicast addresses; and using a new "anycast address" to send a packet to any one of a group of nodes. Это и многое другое вы найдете в книге Configuring IPv6 for Cisco IOS