Summary (1.5)
Warriors of the Net (1.5.1.2)
An entertaining resource to help you visualize networking concepts is the animated movie “Warriors of the Net” by TNG Media Lab. Before viewing the video, there are a few things to consider. In terms of concepts you have learned in this chapter, think about when, in the video, you are on the LAN, on the WAN, on the intranet, on the Internet, and what are end devices versus intermediate devices.
Although all animations often have simplifications in them, there is one outright error in the video. About 5 minutes in, the statement is made “What happens when Mr. IP doesn’t receive an acknowledgment, he simply sends a replacement packet.” This is not a function of the Layer 3 Internet Protocol, which is an “unreliable,” best effort delivery protocol, but rather a function of the transport layer TCP protocol. IP is explained in Chapter 6 and TCP is explained in Chapter 9.
Download the movie from http://www.warriorsofthe.net
Conclusion (1.5.1.3)
Networks and the Internet have changed the way we communicate, learn, work, and even play.
Networks come in all sizes. They can range from simple networks consisting of two computers to networks connecting millions of devices.
The Internet is the largest network in existence. In fact, the term Internet means a ‘network of networks.’ The Internet provides the services that enable us to connect and communicate with our families, friends, work, and interests.
The network infrastructure is the platform that supports the network. It provides the stable and reliable channel over which communication can occur. It is made up of network components including end devices, intermediate devices, and network media.
Networks must be reliable. This means the network must be fault tolerant, scalable, provide quality of service, and ensure security of the information and resources on the network. Network security is an integral part of computer networking, regardless of whether the network is limited to a home environment with a single connection to the Internet or as large as a corporation with thousands of users. No single solution can protect the network from the variety of threats that exist. For this reason, security should be implemented in multiple layers using more than one security solution.
The network infrastructure can vary greatly in terms of size, number of users, and number and types of services that are supported. The network infrastructure must grow and adjust to support the way the network is used. The routing and switching platform is the foundation of any network infrastructure.
This chapter focused on networking as a primary platform for supporting communication. The next chapter will introduce you to the Cisco Internetwork Operating System (IOS) used to enable routing and switching in a Cisco network environment.