Copyright Goodheart-Willcox Co., Inc. 260 Principles of Cybersecurity the actual network address. The second 16 bits are the subnet mask. However, unlike the IPv4 protocol, there are so many addresses available it is unlikely a subnet mask address will ever need to be assigned. Often, an IPv6 address will have a network prefi x that is similar to the CIDR notation. The address in the previous example may be expressed as 2001:203A:0000:0000::/64 or even shorter as 2001:203A::/64. It is important to know how to identify the network type for an IPv6 address. The fi rst quartet in section one indicates what type of address is being used in IPv6. There are three types of network addresses, as summarized in Figure 8-11: • global unicast • link local • site local A global unicast address is a public IPv6 address. Packets with global unicast addresses can be routed and sent on the Internet. They are called unicast because each address must be globally unique. No other host may use a given address. As with IPv4, the IANA controls the designation of these addresses. There are many prefi xes that are used globally, but the most common addresses begin with 2001. A link-local address can be used only on the link (subnet) or broadcast domain. It is new to TCP/IP version 6. This type of address is not forwarded through routers. The interesting fact about these addresses is they are automatically assigned when IPv6 is turned on in the properties of the network interface card. Consider this situation. Your DHCP server is unavailable. In IPv4, you would receive an APIPA address beginning with 169.254.x.x. However, unless other devices on your network also had an APIPA address, you could not communicate Subnet Masks You have been hired as an IT consultant to Great Graphic Designs, a small business focusing on marketing and graphic design. You have determined that this network will need two subnets so the traffic is separated by high-bandwidth needs and general administrative work. These subnets will each have one server, one router, and one dedicated printer. All of these devices will receive a static IP address. Create a report for this customer detailing the network address of each network along with each subnet mask. 1. What private range will you use? 2. Identify the static addresses you will assign to these devices. Case Study Goodheart-Willcox Publisher Figure 8-11. There are three types of addresses in the IPv6 protocol. Summary of IPv6 Address Types Type Public or Private Routing Example Global Unicast A public address. Can be routed outside of the subnet. Any address beginning with 2001 or higher in the first quartet. Link Local A special address automatically created on IPv6 installation. Cannot be routed outside of the subnet. Any address beginning with Fe80, Fe90, FeA0, or FeB0 in the first quartet. Site Local A private address. Can be routed outside of the subnet, but only within the local organization. Any address beginning with FeC0 in the first quartet.