With over 65,000 subnets to choose from, the task of the network administrator becomes one of designing a logical scheme to address the network.

As shown in Figure 1, the example topology will require subnets for each LAN as well as for the WAN link between R1 and R2. Unlike the example for IPv4, with IPv6 the WAN link subnet will not be subnetted further. Although this may “waste” addresses, that is not a concern when using IPv6.

As shown in Figure 2, the allocation of 5 IPv6 subnets, with the subnet ID field 0001 through 0005 will be used for this example. Each /64 subnet will provide more addresses than will ever be needed.

As shown in Figure 3, each LAN segment and the WAN link is assigned a /64 subnet.

Similar to configuring IPv4, Figure 4 shows that each of the router interfaces has been configured to be on a different IPv6 subnet.