tailieunhanh - CCNA 1 and 2 Companion Guide, Revised (Cisco Networking Academy Program) part 71

Cisco Networking Academy Program CCNA 1 and 2 Companion Guide, Revised part 71 is the Cisco approved textbook to use alongside version of the Cisco Networking Academy Program CCNA 1 and CCNA 2 web-based courses. The topics covered provide you with the necessary knowledge to begin your preparation for the CCNA certification exam (640-801, or 640-821 and 640-811) and to enter the field of network administration. | Page 669 Tuesday May 20 2003 2 53 PM Summary 669 Summary In this chapter you learned the following key points The default source for Cisco IOS Software depends on the hardware platform but most commonly the router looks to the configuration commands saved in NVRAM. You can use the show version command to display information about the Cisco IOS Software version that is currently running on the router. You can enter multiple boot system commands to specify the fallback sequence for booting Cisco IOS Software. Routers can boot Cisco IOS Software from Flash memory from a TFTP server and from ROM. You use the show flash command to verify that you have sufficient memory on your system for the Cisco IOS Software that you want to load. With Cisco IOS Software Release and later the naming convention for Cisco IOS contains the following three parts The platform on which the image runs The special capabilities of the image Where the image runs and whether it has been zipped or compressed You can copy a system image back to a network server. This copy of the system image can serve as a backup copy and can be used to verify that the copy in Flash memory is the same as the original file. If you need to load the backup Cisco IOS Software version you can use a variation of the copy command copy tftp flash to download the image that you previously uploaded to the TFTP server. To supplement all that you ve learned in this chapter refer to the chapter-specific Videos PhotoZooms and e-Lab Activities on the CD-ROM accompanying this book. iw Page 670 Tuesday May 20 2003 2 53 PM 670 Chapter 14 Managing Cisco IOS Software Key Terms bootstrap The protocol used by a network node to determine the IP address of its Ethernet interfaces to affect network booting. Flash memory A special type of EEPROM that can be erased and reprogrammed in blocks instead of one byte at a time. Many modern PCs have their BIOS stored on a Flash memory chip so that it can be updated easily