But now you need to know how the servers — the computers responsible for the services on the network — ensure that the clients can find them. Also known as a web application server. Choose the network connection you want to set up or change. Whether wired or wireless, each network and each host has an address. When you buy that Lamborghini over the Web, no one other than the dealer can read your credit card number. The more formal greetings are written down in etiquette books. In this book, we distinguish the Internet from an internet by capitalizing the Internet.
The server is the software that implements the functionality. So what was it about the Internet that enabled the revolution? A server receives an address from autoconfiguration, just as a client does. Some of the people who helped bring this book to market include the following: Acquisitions and Editorial Composition Services Project Editor: Kim Darosett Project Coordinator: Patrick Redmond Acquisitions Editor: Katie Mohr Layout and Graphics: Reuben W. At the assigned date and time for the broadcast, you tune configure your client software to the proper Class D address. See Chapter 4 for a description and an example of a local hosts file. For example, you can connect to 192.
Each field can be a number ranging from 0 to 255. There are always slowpokes and holdouts on new technology. For example, when your computer examines the address 192. . We also provided a list of the steps that the packet travels until it reaches its final destination, shown later, in Figure 8-8. Of course, this process is for telecom companies and nations to figure out and pay for.
You could have a network where all the computers had numeric addresses and no names, but it would make life difficult, almost impossible for most of us. The answer depends on whether you need an address for a private network or a global public network, such as the Internet. We prefer to remain nootral. Hold on to your techie hats. Since the destination computer — www. The Internet is still running out of addresses. Netstat can be a helpful diagnostic tool when you need to know what processes and programs are active on your network.
It does not assume any prior knowledge and it does not leave out any details that might be irrelevant. Chapter 4: Host Name Resolution. The point is that all the packets in a message get to the destination, not how they get there. Look for the daemons in the last column of each line. Applications communicate with services via a port id number. Kerberos Network Authentication Service Kerberos is the three-headed dog that guards the entrance to hell. All other trademarks are the property of their respective owners.
Chapter 5: Need More Addresses? Right-click any local-area connection and click Properties. The other protocols simply have to find the ideal path to the routers it knows about. This file is extremely convenient. Figure 1-2 shows how the east and west coast universities form an extranet. Radio and television stations are assigned permanent addresses so that they can transmit constantly if they choose to.
A Network Figure 4-1: As the network size grows, the number of hosts shrinks. Only the receiver has the private key needed to read the data. But the three fields in the hosts part allow each of those 127 networks to have a ton of computers. The last two digits of each address, the host numbers, are unique. And it still takes time to use and analyze the data they return.
The background color is white. Finally, we get seriously technical with routing protocols, router jargon, and ways to secure routers. With or without a phone? Updating the routing tables can be very intensive and may slow the routers down, and, therefore, slow down part of the Internet. Table 4-5 lists a few well-known port numbers and their accompanying service or protocol. Many organizations also interconnect their e-mail and voice messaging systems with inbound and outbound fax services to create unified messaging solutions. Encrypting your data means converting it to a secret code.
You use a client application, usually a browser, to connect to a Web server. Public networks open to all are by their very nature not very secure. Finally, thank you to Cynthia Woods, a gifted and inspiring musician, who allowed us to use her beautiful Web page as one of our examples. Routers used to be called gateways. The resolver is a client of the server software called a name server. Everyone on board gets free Internet access.
Chapter 4: Nice Names and Appetizing Addresses. Each packet then travels down the layers of the sending host computer , across the network cables, up the layers of the destination host, and into the appropriate application. Suppose that you send a fax to your friend Ken in Tokyo. The Wizard searches for network hardware, and then opens the dialog box shown at the bottom of Figure 6-8. The dotted decimal notation, such as inet 127. Addresses are written as four fields, 8 bits apiece, separated by dots.