Locating and Loading Cisco IOS Software 649 Configuration Register Values The order in which the router looks for Cisco IOS Software images to load depends on the boot field setting in the configuration register. You can change the default configu- ration register setting with the global configuration command config-register. Use a hexadecimal number as the argument for this command, as shown in Example 14-4. The configuration register is set so that the router examines the startup file in NVRAM for boot system options. The configuration register is a 16-bit register in NVRAM. The lowest 4 bits of the configuration register (bits 3, 2, 1, and 0) form the boot field. To change the boot field and leave all other bits set at their original values, follow these guidelines: ■ Set the configuration register value to 0x100 if the ROM monitor needs to be entered. This setting is primarily a programmer’s environment. Boot the operat- ing system manually from the ROM monitor. Use the b command at the ROM monitor prompt to boot the system. This value sets the boot field bits to 0-0-0-0. ■ Set the configuration register to 0x101 to configure the system to boot automati- cally from the limited Cisco IOS Software image in ROM. This value sets the boot field bits to 0-0-0-1. Example 14-3 Booting from ROM Router# configure terminal Router#(config)# boot system rom [Ctrl-Z] Router# copy running-config startup-config Lab Activity Using the boot system Command In this activity, you gather information about the Cisco IOS Image and deter- mine its boot source. You also check the config register settings and document a fallback boot sequence. Example 14-4 Chaging the Boot Field Setting in the Configuration Register Router# configure terminal Router(config)# config-register 0x10F [Ctrl – Z] 1102.book Page 649 Tuesday, May 20, 2003 2:53 PM 650 Chapter 14: Managing Cisco IOS Software ■ Set the configuration register to any value from 0x102 to 0x10F to configure the system to use the boot system commands in NVRAM. This setting is the default. These values set the boot field bits to 0-0-1-0 through 1-1-1-1. If there are no boot system commands in NVRAM, the system will typically look to Flash memory for the Cisco IOS Software image. Table 14-1 shows the boot field values in the configuration register. To check the boot field setting and to verify the config-register command, use the show version command. Displaying the Currently Running Cisco IOS Software Version The show version command, as shown in Example 14-5, displays information about the Cisco IOS Software version that is currently running on the router. This version information includes the configuration register and the boot field setting. Table 14-1 Boot Field Values in the Configuration Register Value Description 0x100 Use ROM monitor mode (manually boot using the b command). 0x101 Automatically boot from ROM (default if router has no Flash memory). 0x102 to 0x10F Examine NVRAM for boot system commands (0x102 is the default if the router has Flash memory). Lab Activity Troubleshooting Config Register Boot Problems In this activity, you check and document the configuration register settings related to boot method and configure the router to boot from Flash. Example 14-5 Configuration Register Router# show version Cisco Internetwork Operating System Software IOS (tm) 2500 Software (C2500-JS-L), Version 12.1(5), RELEASE SOFTWARE (fc1) Copyright (c) 1986-2000 by cisco Systems, Inc. Compiled Wed 25-Oct-00 05:18 by cmong Image text-base: 0x03071DB0, data-base: 0x00001000 2500 Software (C2500-JS-L), chpt_14.fm Page 650 Tuesday, May 27, 2003 2:16 PM Managing Cisco IOS Software Images 651 In the example, the Cisco IOS Software version and descriptive information are highlighted on the second line of output. The screen captured shows Software Release 12.1(5). The next highlighted portion of the output shows the system image file is c2500-js-l, booted using Flash. Notice the portion of the filename that indicates that this image is for a Cisco 2500 platform. As the output of the show version command continues, information is displayed about the type of platform on which the version of Cisco IOS Software is currently running. The final highlighted output provides the targeted results of the command—config- register 0x2142. This information is used to enter configuration register values. Managing Cisco IOS Software Images Routers and switches depend on software for their operation. The two types of software required are operating systems and configuration. The operating system used in almost all Cisco devices is the Cisco Internetwork Operating System (IOS). Cisco IOS Software allows the hardware to function as a router or switch. The Cisco IOS Software file is several megabytes in size. Cisco IOS Software is the platform that ensures that the network provides the connectivity, reli- ability, security, quality of service, scalability, and management capabilities required for applications. ROM: System Bootstrap, Version 5.2(8a), RELEASE SOFTWARE BOOTFLASH: 3000 Bootstrap Software (IGS-RXBOOT), Version 10.2(8a), RELEASE SOFTWARE (fc1) Router uptime is 7 minutes System returned to ROM by reload System image file is "flash:c2500-js-l_121-5.bin" cisco 2500 (68030) processor (revision D) with 16384K/2048K bytes of memory. Processor board ID 03867477, with hardware revision 00000000 Bridging software. X.25 software, Version 3.0.0. SuperLAT software (copyright 1990 by Meridian Technology Corp). TN3270 Emulation software. 1 Token Ring/IEEE 802.5 interface(s) 2 Serial network interface(s) 32K bytes of non-volatile configuration memory. 16384K bytes of processor board System flash (Read ONLY) Configuration register is 0x2142 Example 14-5 Configuration Register (Continued) "flash:c2500-js-l_121-5.bin" NOTE There is no evidence of any config-register setting in output from either the show running-config or show startup-config command. chpt_14.fm Page 651 Tuesday, May 27, 2003 2:16 PM 652 Chapter 14: Managing Cisco IOS Software The software a router or switch uses is referred to as the configuration file or the config. The configuration file contains the instructions that define how the device is to route or switch. A network administrator creates a configuration file that defines the desired functions of the Cisco device. Examples of the functions that can be specified by the config are the IP addresses of the interfaces, routing protocols, and networks to be advertised. The configuration file typically is a few hundred to a few thousand bytes in size. Each of the software components is stored in memory as a separate file. These files are also stored in different types of memory. The Cisco IOS Software image is stored in a memory area called Flash. Flash memory provides nonvolatile storage of a Cisco IOS Software image that can be used as an operating system at startup. Flash allows you to upgrade Cisco IOS Software or to store multiple Cisco IOS Software files. In many router architectures, the Cisco IOS Software image is copied from Flash and run from random-access memory (RAM). A copy of the configuration file is stored in NVRAM to be used as a configuration during startup. This NVRAM configuration is referred to as the startup config. The startup config is copied into RAM at boot time. This configuration in RAM is the configuration used to operate the router. The RAM configuration is referred to as the running config. A single interface to all the file systems that a router uses is provided in Software Release 12 of Cisco IOS Software. This version is referred to as the Cisco IOS File System (IFS). The IFS provides a single method to perform all the file system manage- ment that a router uses. This IFS includes the Flash memory file systems, the network file systems, and reading or writing data. The network file systems include TFTP, remote copy protocol (RCP), and File Transfer Protocol (FTP). The reading or writing data includes NVRAM, the running configuration, and ROM. The IFS uses a common set of prefixes to specify file system devices. Table 14-2 provides an overview of the IFS. Table 14-2 IOS File System Prefix Description bootflash: Boot flash memory. flash: Flash memory. This prefix is available on all platforms. For platforms that do not have a device named Flash, the prefix flash: is aliased to slot0:. Therefore, the prefix flash: can be used to refer to the main Flash memory stor- age area on all platforms. 1102.book Page 652 Tuesday, May 20, 2003 2:53 PM Managing Cisco IOS Software Images 653 The IFS uses the Universal Resource Locator (URL) convention to specify files on network devices and the network. The URL convention identifies the location of the configuration files following the colon as [[[//location]/directory]/filename]. The IFS also supports FTP file transfer. Table 14-3 lists the commands used to manage Cisco IOS Software for Software Release 12.0 and compares them against counterpart com- mands used in Cisco IOS Software releases prior to 12.0. flh: Flash load helper log files. nvram: NVRAM. rcp: Remote copy protocol (RCP) network server. Slot0: First Personal Computer Memory Card Industry Association (PCMCIA) Flash memory card. Slot1: Second PCMCIA Flash memory card. system: Contains the system memory, including the running configuration. Tftp: TFTP network server. Table 14-3 Commands for Managing Cisco IOS Software Release 12.0 and Earlier Pre Cisco IOS Software Release 12.0 Commands Cisco IOS Software Release 12.x Commands configure network (pre-Cisco IOS Software Release 10.3) copy rcp running-config copy tftp running-config copy ftp: system:running-config copy rcp: system:running-config copy tftp: system:running-config continues Table 14-2 IOS File System (Continued) Prefix Description 1102.book Page 653 Tuesday, May 20, 2003 2:53 PM 654 Chapter 14: Managing Cisco IOS Software Cisco IOS Software Naming Conventions Cisco develops many different versions of Cisco IOS Software. Cisco IOS Software supports varied hardware platforms and features. Cisco continuously develops and releases new versions of Cisco IOS Software. Cisco has a naming convention for Cisco IOS Software files to identify the different versions of these Cisco IOS Software files, as illustrated by Figure 14-3. configure overwrite-network (pre-Cisco IOS Software Release 10.3) copy rcp startup-config copy tftp startup-config copy ftp: nvram:startup-config copy rcp: nvram:startup-config copy tftp: nvram:startup-config show configuration (pre-Cisco IOS Software Release 10.3) show startup-config more nvram:startup-config write erase (pre-Cisco IOS Software Release 10.3) erase startup-config erase nvram: write memory (pre-Cisco IOS Software Release 10.3) copy running-config startup-config copy system:running-config nvram:startup-config write network (pre-Cisco IOS Software Release 10.3) copy running-config rcp copy running-config tftp copy system:running-config ftp: copy system:running-config rcp: copy system:running-config tftp write terminal (pre-Cisco IOS Software Release 10.3) show running-config more system:running-config Table 14-3 Commands for Managing Cisco IOS Software Release 12.0 and Earlier (Continued) Pre Cisco IOS Software Release 12.0 Commands Cisco IOS Software Release 12.x Commands 1102.book Page 654 Tuesday, May 20, 2003 2:53 PM Managing Cisco IOS Software Images 655 Figure 14-3 Cisco IOS Software Naming Conventions As Figure 14-3 shows, this Cisco IOS Software naming convention uses different fields in the name: ■ Hardware Platform—The first part of the filename identifies the hardware plat- form. This image is designed for the hardware platform. ■ Feature Set—The second part of the filename identifies the various features that the Cisco IOS Software file contains. You can choose from many different features, and these features are packaged in “software images.” Each feature set contains a specific subset of Cisco IOS Software features. Examples of the feature set cate- gories are as follows: — Basic—Basic is a basic feature set for the hardware platform. Examples of Basic are IP and IP/FW. — Plus—Plus is a basic feature set plus additional features such as IP Plus, IP/FW Plus, and Enterprise Plus. — Encryption—Encryption has the 56-bit data encryption feature sets added to either a Basic or Plus feature set. Examples include IP/ATM PLUS IPSEC 56 or Enterprise Plus 56. The encryption designators are k8/k9 starting with the Cisco IOS Software Release 12.2. k8 is less than or equal to 64-bit encryption on Release 12.2 and up. k9 is greater than 64-bit encryption on Release 12.2 and up. ■ File Format—The third part of the IOS filename indicates the file format. The third part specifies if Cisco IOS Software is stored in Flash memory in a com- pressed format and if the Cisco IOS Software image is relocatable. If the Flash image is compressed, Cisco IOS Software must be expanded during boot as the image is copied to RAM. A relocatable image is copied from Flash memory into RAM to run. A non-relocatable image is run directly from Flash memory. 1102.book Page 655 Tuesday, May 20, 2003 2:53 PM 656 Chapter 14: Managing Cisco IOS Software ■ Version and Release—The fourth part of the IOS filename identifies the version number and release of Cisco IOS Software. As Cisco develops newer versions of Cisco IOS Software, the numerical version number increases. Managing Configuration File Using TFTP In a Cisco router or switch, the active configuration is in RAM. The default location for the startup configuration in a Cisco router or switch is NVRAM. In the event the configuration is lost, you should back up this startup configuration. You can store one of these backup copies of the configuration on a TFTP server. You can use the copy running-config tftp command to back up the configuration. The steps to perform this backup process are as follows: Step 1 Enter copy tftp running-config. Step 2 Enter the IP address of the TFTP server that is to store the configuration file at the prompt. Step 3 Enter the name to assign to the configuration file or accept the default name. Step 4 Confirm the choices by typing yes each time. Example 14-6 demonstrates the actual process. You can restore the router configuration by loading the backup configuration file from a TFTP server. The steps you can take to restore the configuration are as follows: Step 1 Enter copy tftp running-config. Step 2 Select a host or network configuration file at the prompt. Step 3 At the system prompt, enter the IP address of the TFTP server where the configuration file is located. Step 4 At the system prompt, enter the name of the configuration file or accept the default name. Step 5 Confirm the configuration filename and the server address that the system supplies. Example 14-6 Backing Up the Startup Configuration on a TFTP Server Cougar# copy running-config tftp Address or name of remote host [] 192.168.119.20 Destination file name [Cougar-config]? !!!!!!!!!!!!!!!!!!!!!!!! 624 bytes copied in 7.05 secs Cougar# N O TE If the router config file is missing or if the erase startup-config and reload commands have been used, the router will not have any interfaces config- ured. TFTP requires IP to make a connec- tion, so you will need to connect to the router using the con- sole port and config- ure an IP address for the interface that will provide access to the TFTP server. 1102.book Page 656 Tuesday, May 20, 2003 2:53 PM Managing Cisco IOS Software Images 657 Example 14-7 demonstrates the process of restoring the configuration from a TFTP server. To copy the configuration file from the TFTP server back to the router, perform the fol- lowing steps: Step 1 Enter configuration mode by entering the copy tftp running-config command. Step 2 At the system prompt, select a host or network configuration file. The network configuration file contains commands that apply to all routers and terminal servers on the network. The host configuration file contains commands that apply to one router in particular. At the system prompt, enter the optional IP address of the remote host where the configuration file is located. In Example 14-8, the router is configured from the TFTP server at IP address 131.108.2.155. Step 3 At the system prompt, enter the name of the configuration file or accept the default name. The filename convention is UNIX-based. The default filename is hostname -config for the host file and network -config for the network configuration file. In the DOS environment, the server filenames are limited to eight characters plus a three-character extension. An example is router.cfg. Confirm the configuration filename and the server address that the system supplies. Notice in Example 14-8 that the router prompt changes to tokyo immediately. This change is evidence that the reconfiguration happens as soon as the new file is downloaded. Example 14-7 Restoring the Startup Configuration from a TFTP Server Cougar# copy tftp running-config Address or name of remote host [] 192.168.119.20 Source filename []? Cougar-confg Destination filename [running-config]? Accessing tftp://192.168.119.20/GAD-confg… Loading GAD-confg from 192.168.119.20 (via FastEthernet 0/0): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! [OK-624 bytes] 624 bytes copied in 9.45 secs Cougar# 1102.book Page 657 Tuesday, May 20, 2003 2:53 PM 658 Chapter 14: Managing Cisco IOS Software Example 14-8 demonstrates the process of copying the configuration file from a TFTP server. Managing Configuration Files with HyperTerminal Capturing the output of the show running-config command is another way to create a backup copy of the configuration. You can perform this backup from the terminal ses- sion by copying the output, pasting to a text file, and saving the text file. However, this file needs some editing done before you can use it to restore configuration to the router. Figure 14-4 shows an example of cutting and pasting configurations. To capture the configuration in HyperTerminal text that is displayed on the screen to a text file, use the following steps: Step 1 Select Transfer. Step 2 Select Capture Text. Step 3 Specify the name for the text file to the capture configuration. Step 4 Select Start to start capturing text. Step 5 Display the configuration to the screen by entering show running-config. Step 6 Press the space bar when each “-More -” prompt appears, which contin- ues with the configuration until the end is reached. Step 7 When the complete configuration has been displayed, stop the capture using the following steps: a. Select Transfer. b. Select Capture Text. c. Select Stop. Example 14-8 Copying the Configuration File from a TFTP Server tokyo# copy tftp running-config Host or network configuration file [host]? IP address of remote host [255.255.255.255]? 131.108.2.155 Name of configuration file [Router-config]? tokyo.2 Configure using tokyo.2 from 131.108.2.155? [confirm] y Booting tokyo.2 from 131.108.2.155:!! [OK-874/16000 bytes] tokyo# Lab Activity Managing Configuration Files with TFTP In this activity, you copy a router configuration file to a TFTP server and then configure the router by copying the file back from the TFTP server. 1102.book Page 658 Tuesday, May 20, 2003 2:53 PM . tftp:/ /19 2 .16 8 .11 9 .20 /GAD-confg… Loading GAD-confg from 19 2 .16 8 .11 9 .20 (via FastEthernet 0/0): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! [OK- 624 bytes] 624 bytes copied in 9.45 secs Cougar# 11 02. book. of configuration file [Router-config]? tokyo .2 Configure using tokyo .2 from 13 1 .10 8 .2 .15 5? [confirm] y Booting tokyo .2 from 13 1 .10 8 .2 .15 5:!! [OK-874 /16 000 bytes] tokyo# Lab Activity Managing Configuration. Software Release 12 .2. k8 is less than or equal to 64-bit encryption on Release 12 .2 and up. k9 is greater than 64-bit encryption on Release 12 .2 and up. ■ File Format—The third part of the IOS