Subnetting, as this process is more commonly called, is a remarkably logical and mathematical process. Understanding the mathematics of subnetting helps you develop and implement efficient subnetting schemes that make better use of available address spaces. That is the explicit goal of subnetting: to use an address space more efficiently. Unfortunately, subnetting is the most confusing and least-understood aspect of IPv4 . This is largely due to the fact that it makes sense only when viewed in binary numbers, yet most people think in terms of decimal numbers. For that reason alone I rely extensively on the use of binary-to-decimal translations to demonstrate the concept and applications of subnetting throughout this chapter. (more…)

Having examined the mathematics upon which the IP address space is founded, it is time to explore its hierarchical organization. The hierarchy is best described as being compound, because there are two aspects:

• Two levels of addressing within each IP address.

• Classes of addresses based on differing bit allocations to the two levels of addresses. Having segmented the address’s bit string into four 8-bit components makes it very easy to create address classes because you have logical groupings to work with.

Each of these hierarchical aspects is explored in the following sections. (more…)

IP and its addressing scheme evolved slowly, sometimes even erratically, over time. They were not, contrary to any current appearances, carefully designed prior to implementation! For example, RFC 1, published in April 1969, tells us that the original IP address space was specified at just 5 bits! As you will see in this chapter, that’s enough for just 32 addresses! Strange as that might sound, in 1969 that was more than enough for the embedded base of computers that were being internetworked. Over time, the number of bits allocated to host addressing was increased to 6, and then 8, and finally up to the familiar 32-bit format that is in use today. (more…)

Making publicly available standards documents that stipulate every nuance of a technology is known as open standards. Open standards offer tremendous benefits that have been proven time and again since the introduction of this concept. In the days before the Internet, the previous paradigm was tightly integrated proprietary platforms. In other words, every aspect of a networked computing architecture (including endpoint devices, cable interfaces, computing platforms, operating systems, applications, and printers) was tightly linked by the manufacturers. You couldn’t mix and match components from different manufacturers; you had to select one vendor for all your needs. (more…)

The way that technical standards are developed for the Internet might seem arcane from the outside looking in, but this process is eminently logical, and it has served the Internet well for years. This process is documented in the IETF’s RFC 2026, which is also currently the Internet’s BCP #9. This document can be accessed at www.ietf.org/rfc/rfc2026.txt.

If the terms RFC and BCP are alien to you, read on. The remainder of this chapter is devoted to helping you understand the inner workings of this vital function. The roles of Internet drafts, RFCs, STDs (standards), and BCPs are all explored and explained. (more…)

Numerous organizations, standards bodies, and even corporations function in different capacities. All of them contribute in some way to the Internet. Some allocate domain names (such as cisco.com) or assign IP addresses to the Internet’s end users. Others create the technologies that make the Internet work or that let you use the Internet. All these entities are integral to the Internet’s operation. We’ll look at each one in this chapter, but only one can truly be considered the Internet’s caretaker. That organization is the Internet Engineering Task Force (IETF). (more…)

We will go through some additional settings that are useful in public hotspot solutions, which you probably were not prompted for during the initial setup. You might need to refer to your wireless router documentation for specific instructions on some of the settings, because all wireless routers work differently. (more…)

To set up your wireless router, follow the manufacturer instructions that are included with the product. Some vendors might have written guides, and some might want you to use a CD that will help with the wireless router setup. The installation instructions will most likely have you configure some initial settings, but you will need to keep in mind several things, as discussed in the following list. Do not worry if you are not prompted during the setup to configure all these items, because you will have a chance to change all the settings later.

• Do not use security or encryption methods.

• Use a service set identifier (SSIDnetwork name) that describes your business/organization or attentions. For example, a café might use “Free Hotspot at Bob’s Café.” If the hotspot is being put in just for the local youth club, you might want to use something such as “Youth Club Hotspot.”

• Configure a channel that is not being used by other nearby wireless networks. You should also try to use the nonoverlapping channels of 1, 6, and 11. However, try to avoid channel 6, because it is the default channel that most wireless devices use; therefore, it is likely the most congested channel.

• Use mixed mode so that users who have either B or G wireless adapters can connect to your hotspot.

The hardware for the simple free hotspot solution consists of a wireless router.

When looking for the equipment, it is best to stick with the recommended products. These products are used in this book when showing applicable configuration screens, so if you are new to wireless, it is highly recommended that you use this same equipment. (more…)

You might already have an Internet connection established in your home. That is not much different from the Internet connection you could have for your hotspot. Whether or not you have experience with various Internet connections, you need to pay a little more attention to the features and choose a type of connection that will satisfy the needs of your hotspot users. (more…)