In Figure 14-5, what if • B’s best path to F is through C? • C’s best path to F is through E? • E’s best path to F is through D? • D’s best path to F is through B? Figure 14-5 Control Plane Routing Loop Why would router E point toward D to […]
Figure 14-6 illustrates one reason IPv6’s designers wanted to eliminate NAT. Figure 14-6 Embedded IP Addresses Before and After NAT Some applications embed the source and destination addresses within the data portion of the packet. If the source and destination addresses are translated, the addresses in the header and the data portion of the packet […]
The Transmission Control Protocol (TCP) is a connection-oriented transport protocol. Connection-oriented protocols are useful for • Transmitting large amounts of data, such as large files. • Transmitting continuing streams where losing information cannot be tolerated, such as stock market information. For instance, TCP is used for carrying emails and websites because these kinds of data […]
Take the quiz (either here or use the PTP software) if you want to use the score to help you decide how much time to spend on this chapter. Appendix A, “Answers to the ‘Do I Know This Already?’ Quizzes,” found at the end of the book, includes both the answers and explanations. You can […]
TCP has several significant limitations, including • A three-way handshake is required for all connections, even between previously connected hosts. • Multiple TCP sessions, each requiring a three-way handshake, are required to carry multiple data streams, as shown in Figure 14-11. • TCP does not automatically encrypt data. A second protocol, such as Transport Layer […]
Web applications and IXPs require large-scale networks to connect thousands—or even millions—of devices. Public and private clouds also need to build these large-scale networks to connect large numbers of servers. Note Chapter 17, “Cloud Computing, ” covers public and private clouds. These operators do not use traditional network designs to connect large numbers of servers […]
Much of the data people use the modern Internet to access resides in data centers, and users access the data through the Hypertext Markup Language (HTML). Note Chapter 15, “Application Transport, ” discusses HTML and the Hypertext Transfer Protocol (HTTP). Content providers, such as search engines and social media networks, develop and manage some of […]
In the early 1970s, scientists and engineers began working on a new computer networking technology. They designed this technology around a basic three-layer model: • The physical layer would handle the physical process of carrying data between two interfaces. • The network layer would provide an interface between physical transports (there were many at the […]
Take the quiz (either here or use the PTP software) if you want to use the score to help you decide how much time to spend on this chapter. Appendix A, “Answers to the ‘Do I Know This Already?’ Quizzes,” found at the end of the book, includes both the answers and explanations. You can […]
A butterfly fabric is like a Clos fabric but has five stages instead of three. Figure 13-7 illustrates a small butterfly fabric. Note Some network engineers called a butterfly a five- stage Clos. For clarity, this book always calls a three-stage spine-and-leaf a Clos and a five-stage the design described in this section a butterfly. […]
