Intermediate Networking

You'll pick up right where the last lesson left with a discussion on how a unit of computer data—called a packet—gets from one computer to another. You'll learn all about how packets are formed, how packets are sometimes chopped then reassembled to go across WAN links, and how the receiving computer handles packets upon arrival. You'll also learn why the network's most important device is the router.

This lesson is dedicated to helping you understand how routers operate. You'll learn all about how routers create a virtual map of the entire Internet. You'll also see how routers connect to different network types—an Ethernet segment and an ATM link, for example—and transmit data across those different mediums. The lesson will then discuss why routers have their own special languages, called routing protocols.

In this lesson, you'll learn the language of routers: routing protocols. You'll learn why some routing protocols are appropriate for smaller networks, and why very large networks require specialized routing protocols. You'll also learn about the two most revealing measurements of a router's capability: latency and packets per second (pps).

You've heard of TCP/IP, but its details may seem mysterious. After you complete this lesson, those mysteries will be banished forever! You'll learn about IP addressing, the four primary IP address classes, and all about the various protocols that come packaged within TCP/IP. Prepare to demystify TCP/IP!

Security is on everyone's mind these days, so in this lesson, you'll learn the fundamentals of how computers enforce security. You'll learn what a security descriptor is and how it can allow some people to only read a document, while others can delete or modify the document as much as they like. You'll also learn the difference between a security implementation and security protocols. Finally, you'll find out how security operates in a Windows environment, including exactly what happens during log on, authentication, and authorization.

In this lesson, you'll explore encryption, a method used to secure data for transmission over the Internet. You'll learn about various encryption schemes and get firsthand knowledge of how a chunk of data gets encrypted, how it gets decrypted on the receiving end, and how this process can be made secure. You'll also learn how Secure Sockets Layer (SSL) makes it safe for you to order merchandise online, and how SSL ensures that your connection to the seller's website is secure.

The Internet is a great public network, but what if you need it for private communication? For example, what if a salesman needs to make a private connection to their company's network to check on special bulk pricing? In this lesson, you'll learn how you can create a virtual private network out of your Internet connection. You'll get a hands-on view of how these private connections are made, and why they're so useful.

The Internet, and almost every other network today, uses Domain Name System (DNS) to translate human-readable names (like www addresses) into IP addresses that computers can use. It's important to understand how this system works, so in this chapter you'll learn details about how DNS operates. You'll learn how resource records are the building blocks of DNS, and how DNS scales to the entire Internet by being broken into zones.

This lesson will expand on the discussion of DNS. Here you'll learn about the most important types of resource records, including A records, SOA records, and others. You'll also learn about the two types of DNS queries: recursive and iterative. There are many other resource record types, and you'll learn about those as well. By the end of the lesson, it'll be clear just how important DNS is to people's daily lives!

In this lesson, you'll learn how Internet servers operate, including how a web page is requested and transmitted to your computer, then displayed on your screen. You'll also learn about the two primary web protocols—HTTP and HTML. There are other Internet-based services, such as email servers, news servers, and instant messaging, and you'll investigate those in this lesson, too.

Have you ever wondered about the difference between a desktop computer and a server? Have you heard of cloud computing, but don't know exactly what it means? The final lesson will go over the differences between server-class operating systems and server-class computers and go in-depth about the various hardware components that comprise a true server-class computer. Understanding why a desktop computer shouldn't be used as a departmental server is important! You'll also learn what cloud computing is, why it's such a compelling platform, and how data centers provide all that computing power.