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IPv6 Basic Subnetting and Examples

Article Description

This quick and dirty look at the notation differences between IPv4 and IPv6 will ensure that you know what you need to to run IPv6 effectively on your network. With the standard decimal notated IPv4 address and network. and the standard hexadecimal notated IPv6 address and network, it can get confusing. Sean Wilkins explains two of the most commonly used IPv6 ranges and applications, and how they can be used to calculate IPv6 addressing ranges.
Global Unicast Addressing Plan Example

Global Unicast Addressing Plan Example

In this section an example Global Unicast addressing plan will be shown. The topology for the Acme Corporation that will be used in these examples is shown in Figure 4.

Figure 4: Acme Corp – Internet Connectivity

Like the previous example, the Acme Corp still has four major operations centers. The difference in this example is that the traffic is able to directly connect to the Internet and thus must use globally routable addresses. To avoid using anyone’s actual IPv6 Global assignment, the IPv6 documentation prefix will be used in this example: 2001:0DB8::/32. For the purposes of this example, this prefix will be used in place of an actual /32 prefix assigned by ICANN and an RIR to a local ISP. The ISP would then be responsible to use this prefix, form a plan for the bits between /32 and /48, and assign end user organizations /48 network ranges. For this example the ISP decided to assign the Acme Corp the 2001:0DB8:C21A::/48 network; Acme is then free to divide this space up over the next 16 bits. An example of this type of assignment is shown in Table 2.

Table 2: Acme Corp - IPv6 Global Unicast Address Assignment


IPv6 Unique Local Address Range Assignment



San Francisco


New York