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Hour 19
Internet/Intranet Troubleshooting

I remember when a co-worker loudly proclaimed that the Internet was a waste of time and that all of us who were fascinated with it had best find another line of work. Well, although he’s a nice enough guy, he’s not exactly a terrific fortune teller. The Internet has been more successful than any of us ever dreamed.

The basic idea behind this hour is that the same backhoes and steamrollers used to fix the “information superhighway” at large are also used to troubleshoot your local streets and byways. We’ll start off by defining the Internet versus intranets and quickly get into troubleshooting techniques.

Definitions

Nobody needs to define the Internet for you. The source of life, the Mecca of computer civilization, the wellspring from which information flows, the fount of all packets good and ill, is the Internet. In the space of one kid’s college career, the Internet has gone from being a pretty nice resource for computer geeks, to being indispensable for geeks, to being indispensable for everyone. Many folks used to call the Internet a “noncritical resource,” but that’s no longer the case, particularly if your business relies on email or a Web page to keep in touch with customers. Nowadays, it’s a vital resource; if it’s down, oftentimes folks can’t do their work. For example, this book was edited largely over the Internet. Had it been down—I don’t want to think about it!

The millions and millions of TCP/IP-connected computers and networks in the world all network in pretty much the same way that we’ve been talking about since Hour 1, “The Telephone Analogy: Becoming Familiar with Basic Networking Concepts,” but just on a different scale. When your workstation sends a request for a Web page to a server at www.microsoft.com, a name-to-IP-address DNS lookup is done; then a TCP/IP call is sent up to the server, assisted by anywhere from three to a dozen routers in between.

Should troubleshooting your Internet connection differ from the TCP/IP troubleshooting that you’ve already learned? Not fundamentally. However, with the next level of complexity comes the next level of troubleshooting techniques. In a nutshell, a fault with the Internet connection at your location definitely involves your ISP (Internet service provider) but may not be its fault. We’ll talk about the types of firewalls that you might have in your shop and then discuss ways to point the finger at routing problems, name resolution problems, and whether you should call your ISP into the fray for a given problem.

Intranet = Internal

The word intranet and its successor extranet (a network connecting you and a business partner) are marketing terms that have always confused me. True, intra means within, and extra means without, but so what? In our data center, we’ve usually got an idea of which applications run externally—we call them “public access.” In my (admittedly twisted) mind, you might as well call your neighbor’s lawn an interlawn, your own lawn an intralawn, and the border between your lawns an extralawn. Give me a break!

Seriously, the term intranet does have its uses—but so does the phrase “my network.” All it means is that you’re using Internet-like applications within the boundaries of your own network—you’re using technologies that grew up on the Web. An intranet can be as useful as a Web-enabled telephone directory of all employees, complete with search capabilities, or it can be as useless as a static Web page welcoming you to the Frobozz Magic Intranet. Whatever your intranet does, it’s likely that you want it to keep on truckin’.

Many of the tools used for diagnosing your Internet connection are applicable to intranet troubleshooting, so read the Internet section carefully. (The techniques covered in Hour 18, “Lots of Different People in Your Neighborhood: In-Depth Application Troubleshooting,” are also very applicable to troubleshooting intranets.)

With that said, later on in this hour, we’ll cover troubleshooting that’s particular to your local network: your internal and external Web services, your email, and the problems that dialup networking users might face.

Cyber Chaos

With all the fancy terms surrounding the Internet, it can be easy to lose sight of the fact that it’s just one big TCP/IP network. Let’s look at some specific TCP/IP troubleshooting techniques that can pinpoint Internet problems in your shop.

To start with, we’ll need to identify what kind of Internet connection your shop has. Once you know what type of Internet connection you have, you’ll be better able to identify which of the following techniques are right for you.

Unless you work for a huge multinational company with fault-tolerant Internet connections all over the place, you probably have just one firewall and one domain name (company.com).

Actually, if you happen to work for a huge conglomerate with thousands of dedicated IT (Information Technology) staff members, you’ll probably have to read this book in a plain brown wrapper, and you might not have an official chance to practice what you’ve learned outside of your local area network. The chances of you being allowed to touch network gear or get directly outside the firewall in this type of environment are slim to none. Remember: If any of you are caught or killed, the secretary will deny all knowledge of your actions. This book will self-destruct in five seconds.


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