ccna 200 301 topics

ccna 200 301 topics.Cisco routers use Cisco IOS software as their operating system (OS). For the vast majority of cases, this book and ICND1 will ignore some of the details of using the IOS as a terminal. However, this book has also discussed the networking capabilities of the IOS at great length. Now, let's focus on basic device management issues, such as how to upgrade the IOS, and how the router loads the IOS in a powered-up state.Unlike other OSes you may have used, the Cisco IOS exists as a single file called an IOS image. The software upgrade process involves such steps as copying the newer version of the IOS image to flash memory, configuring the router to tell it which IOS image to use, and deleting the older IOS image after confirming that the newly released version is working properly. When the router is powered on, the boot process on the router is ready to pick the correct I0S image in order to overcome and fix the problem, regardless of the process failure for whatever reason.The first part of this chapter first discusses how to upgrade the Cisco I0S software on the router, and then discusses the router's boot process. Tip: The focus of this chapter is on the router, not the switch. However, many of the concepts can be applied to switches as well.Upgrading the Cisco I0S Software Image to Flash MemoryRAM Flash ROM NVRAM(working memory and running (Cisco . QS software ) (bootloader and ROMMON) (boot configuration )Configuration )Cisco routers typically do not have hard drives, but instead use different types of memory depending on their purpose, as shown in Figure 20-1. Figure 20-1 Types of Router Memory and Their Different Purposes Routers typically store IOS images in flash memory. Flash memory is erasable, permanent memory that is used to store files that need to be retained even after the router is powered off. Cisco deliberately uses flash memory in its products instead of hard disk drives because there are no removable parts in flash memory, so there is less probability of failure compared to hard disk drives. Some router models use internal flash memory chips, while others use external flash memory slots that are capable of supporting flash cards commonly found in consumer electronics. The new routers also support flash drives that connect to external USB ports. In addition, Cisco routers can store their IOS images on external servers that must be able to connect over a network, typically using the TFTP or FTP protocols. However, external servers are often used for testing, or to recover from problematic states, which are often caused by IOS files in flash memory. In production, almost every router is loaded with an IOS image, which is stored in the only large permanent storage available on the router: flash memory.Do I already know this? Answers to the quiz: (1) b (2) b (3) d (4) d (5) a (6) a (7) b11.2 Basic Content 409