Review Questions
Use the questions here to review what you learned in this chapter. The correct answers and solutions are found in the appendix, Answers to Chapter Review Questions. 1. Which three statements accurately describe WANs a. The companies in which WANs are implemented usually own the WANs. b. WANs connect devices that are separated by wide geographic areas. c. WANs use the services of carriers such as telephone companies, cable companies, satellite systems, and network providers. d. WANs generally...
Configuring a Cisco Router
When the hardware installation is complete and the Cisco router has the initial configuration, you can begin configuring the router for a specific internetwork. You must be familiar with the Cisco IOS command-line interface (CLI), its modes, and its operation before configuring more advanced features such as IP routing. The following sections describe how to implement a basic configuration for a Cisco router. From privileged EXEC mode, you can enter global configuration mode, providing access...
Starting a Switch
A Cisco Catalyst switch goes through its startup routine when the switch is turned on. When the startup is complete, the initial software settings can be configured. Recognizing that the switch startup has completed without error is the first step in deploying a Catalyst switch. The switch must start successfully and have a default configuration to operate on the network. The following sections describe how the switch starts up and how to verify its initial operation. Physical Startup of the...
Operating Cisco IOS Software
Understanding the enterprise network environment provides a perspective about the need for greater functionality and control over network components, delivered through more sophisticated network devices such as switches. Cisco IOS Software is feature-rich network system software, providing network intelligence for business-critical solutions. The following sections compare the functionality of switches and devices in small office, home office (SOHO) network environments with network components...
Info
In circuit switching, a dedicated path is established, maintained, and terminated through a carrier network for each communication session. Only the access path is a dedicated physical circuit the network uses some form of multiplexing technology within the cloud. Circuit switching operates much like a normal dialup telephone call and is used extensively in telephone company networks. Circuit switching establishes a dedicated physical connection for voice or data between a sender and receiver....
Understanding Cisco Router Security
After you secure physical access to your network, you must ensure that access to the Cisco router through the console and vty ports is secure. In addition, you must ensure that unused router ports do not become a security risk. The following sections describe router Improper and incomplete network device installation is an often-overlooked security threat. Software-based security measures alone cannot prevent network damage because of poor installation. This topic describes how to mitigate...
Understanding Switch Security
After physical access has been secured, there is a growing need to ensure that access to the switch ports is secure through any EXEC session connection, such as securing the console (CON) port and securing the Telnet (VTY) ports. In addition, it is important to ensure that unused switch ports do not become security holes. The following sections describe how to mitigate hardware, environmental, electrical, and maintenance-related security threats to Cisco IOS devices. Improper and incomplete...
Peerto Peer Communication
For data to travel from the source to the destination, each layer of the OSI reference model at the source must communicate with its peer layer at the destination. This form of communication is referred to as peer-to-peer communication. During this process, the protocols at each layer exchange information, called protocol data units (PDU), between peer layers, as shown in Figure 1-23. Data packets on a network originate at a source and then travel to a destination. Each layer depends on the...
