1. Page 110/19/2015 Chapter 5 CCNA2 Chapter 5 Managing Cisco IOS Software

2. Page 210/19/2015 Chapter 5 Bootstrapfrom ROM locate & load IOS Determined from config register; 0x2102 says to look in NVRAM for boot system cmds; if none then Default sequence: flash TFTP Server ROM (subset of IOS) locate & load configuration file or enter ‘Setup’ mode NVRAM TFTP Server console Default sequence: Router Startup Sequence

3. Page 310/19/2015 Chapter 5 Use the configuration registers (show version) that is saved in NVRAM to determine the sequence ( either from flash, ROM monitor, or RAM ). If NVRAM lacks boot system commands that the router can use, the system by default uses the the IOS software in flash memory. One can modify the sequence via the ‘configuration-register’ command: Router# configure terminal Router(config)# boot system flash IOS_filename Router(config)# boot system tftp IOS_filename tftp_address Router(config)# boot system rom [Ctrl-Z] Router# copy running-config startup-config Loading IOS Software

4. Page 410/19/2015 Chapter 5 Remember multiple images can be stored, so specify name Specify name of image, plus IP address of server Boot Options

5. Page 510/19/2015 Chapter 5 To find out if there are boot system commands configured on a router, enter any one of the following commands: –show running-config –show startup-config Boot System Command

6. Page 610/19/2015 Chapter 5 The configuration register is a 16-bit register located in NVRAM. The lowest four (4) bits of the register forms the boot field. To ensure that the upper 12 bits are not changed, first retrieve the current values of the configuration register using the show version command. Then use the config-register command at the global configuration mode. Configuration Register 2 1 0 2 0010 000100000010 Configuration Register Binary

7. Page 710/19/2015 Chapter 5 There are 3 monitor modes: ROM monitor 0xnnn0 ROM 0xnnn1 from NVRAM 0xnnn2 TO 0xnnnF NOTE: When one enters the ROM monitor mode, use the b command at the ROM monitor prompt. For example to enter the ROM mode do: Router(config)# config-register 0x2101 Configuration Register

8. Page 810/19/2015 Chapter 5 If the config-register is set to 0x2102 It tells the router to look in the startup configuration for boot system commands. Configuration Register To enter ROM monitor mode Vargas(config)# config-register 0x2100 Vargas(config)# exit Vargas# copy run start Destination filename [startup-config]? Building configuration... [OK] Vargas# reload Proceed with reload? [confirm] rommon 1 >

9. Page 910/19/2015 Chapter 5 If a router doesn’t boot, then the following could be the problem: configuration file has missing or incorrect boot system statement incorrect configuration register value corrupted flash image hardware failure Possible solutions: show run, and look for a boot system statement. If incorrect, go to global configuration mode and put a no in front of the statement. show version, and see if the configuration register is incorrectly set if the flash is corrupted, one will get an error message during boot none of the above, then it is possibly a hardware error. Trouble Shooting IOS boot failures

10. Page 1010/19/2015 Chapter 5 Remember the configuration register is shown in show version. The configuration register is NOT displayed by a show run nor show start. Trouble Shooting IOS boot failures

11. Page 1110/19/2015 Chapter 5 There are two (2) types of software required for switches and routers to operate: 1.Operating system (IOS) 2.Configuration (configuration of the router/switch) Running config is in RAM. Startup config is in NVRAM. IOS image is in flash Some of the functions specified by the config file are: IP addresses of the interfaces Routing protocols Networks to be advertised IOS File System Overview

12. Page 1210/19/2015 Chapter 5 Beginning with version 12 of the IOS, a single interface to all the file systems that a router uses is provided in Cisco IOS File System (IFS). Some prefixes used: Bootflash: flash: ftp: nvram: rcp: Slot0: Slot1: system: Tftp: Trouble Shooting IOS boot failures

13. Page 1310/19/2015 Chapter 5 C2600-js-l_121-3.bin Hardware Platform (2600) Feature Set (enterprise w/ extended features) File format (relocatable; not compressed) Version number (12.13) IOS Naming Convention

14. Page 1410/19/2015 Chapter 5 From the router to TFTP: copy running-config tftp at the prompt, enter the IP address of the TFTP server enter the name to assign to the config file or accept default name confirm each choice by typing yes each time From TFTP server to the router: copy tftp running-config at the prompt, select a host or network config file at the system prompt,enter the IP address of TFTP server where the configuration file is located at the system prompt, enter the name of the config file or accept the default name confirm the configuration filename & the server address that the system supplies Backing up Configuration Files

15. Page 1510/19/2015 Chapter 5 Before using TFTP to upload an IOS: Check memory first (show flash) Ping the IP address of your TFTP server Know the name of the file you are copying from, make sure it is in the default directory Using TFTP to Upload an IOS

16. Page 1610/19/2015 Chapter 5 Troubleshooting IOS boot failures A TFTP service should run on this server. See http://www.solarwinds.com/downloads/ http://www.solarwinds.com/downloads/

17. Page 1710/19/2015 Chapter 5 Another way to managing config files is to use the Transfer command of the HyperTerminal screen. Backing up Configuration Files

18. Page 1810/19/2015 Chapter 5 To restore or upgrade the IOS file, backup the original file!!!! Do the copy flash tftp router will prompt for the IP address of the TFTP server. router will prompt to erase flash if there is not sufficient room available a series of e’s will appear to show the erase process. ! Will be displayed while the file is downloaded. After the new flash is down loaded it is verified. Upgrading/Restore IOS Files

19. Page 1910/19/2015 Chapter 5 It is a good idea to back up the current IOS before copying a new one, in case the copy fails - flash is erased BEFORE the actual copy begins. Backing up the IOS to a TFTP Server

20. Page 2010/19/2015 Chapter 5 If the IOS image in flash has been erased or corrupted, one can restore the file from the ROM monitor mode. It is identified by: rommon 1 > As an example: rommon 1 > boot flash:c2600-is-mz.121-5 One can also us Xmodem from ROMmon: rommon 1 > Xmodem -c c2600-is-mz.122-10a.bin Upgrading/Restore IOS Files

21. Page 2110/19/2015 Chapter 5 X-Modem