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Selecting Device Addresses

When determining the addresses to be assigned within the network, similar devices should be grouped into address ranges. These address ranges should be distinguishable. By exam-ining an address, you should be able to determine what kind of device originates the packet.

Addresses for Servers and Peripherals

Any network resource, such as a server or a printer, should have a static IPv4 address. The client hosts access these resources using the IPv4 addresses of these devices. Therefore, predictable addresses for each of these servers and peripherals are necessary.

Servers and peripherals are a concentration point for network traffic. There are many pack-ets sent to and from the IPv4 addresses of these devices. When monitoring network traffic with a tool like Wireshark, a network administrator should be able to rapidly identify these devices. Using a consistent numbering system for these devices makes the identification easier.

Addresses for Hosts That Are Accessible from the Internet

In most internetworks, only a few devices are accessible by hosts outside the corporation. For the most part, these devices are usually servers of some type. As with all devices in a network that provides network resources, the IPv4 addresses for these devices should be static.

In the case of servers accessible by the Internet, each of these must have a public space address associated with it. Additionally, variations in the address of one of these devices will make this device inaccessible from the Internet. In many cases, these devices are on a network that is numbered using private addresses. This means that the router or firewall at the perimeter of the network must be configured to translate the internal address of the serv-er into a public address. Because of this additional configuration in the perimeter intermedi-ary device, it is even more important that these devices have a predictable address.

Addresses for Intermediary Devices

Intermediary devices are also a concentration point for network traffic. Almost all traffic within or between networks passes through some form of intermediary device. Therefore, these network devices provide an opportune location for network management, monitoring, and security.

Most intermediary devices are assigned Layer 3 addresses, either for the device manage-ment or for device operation. Devices such as hubs, switches, and wireless access points do not require IPv4 addresses to operate as intermediary devices. However, to access these devices as hosts to configure, monitor, or troubleshoot network operation, they need to have addresses assigned.