Boot start marker cisco что это

Cisco IOS Cookbook, 2nd Edition by Kevin Dooley, Ian Brown

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Booting a Different IOS Image

Problem

You want to boot using an alternate IOS image.

Solution

To specify which IOS image the router should load next time it reboots, use the boot system command:

The sequence of the boot system commands is extremely important, as the router will attempt to load the IOS images in the order that they appear in the configuration file.

Discussion

The router can store as many IOS images in its flash memory as there is space to hold. If there is only one file, it can safely assume that this must be the IOS image to load. However, if the router has several images in its flash storage, you need to specify which one it should load, or the router will simply select one. This is particularly true on routers that have additional flash memory in the form of PCMCIA cards, which can hold many files, not all of which are even necessarily IOS images.

With the default configuration register settings, the router will attempt to load the first accessible IOS image it finds in its flash storage. However, loading the first available image might not be appropriate. For instance, in our last recipe we showed that, if you have space, you can download a new IOS image without erasing old images. In this case, you probably want the router to load the newer IOS image. And it would be better still if the router would try the new image first, and revert to the old image if the first one failed to load correctly for any reason. The boot system command allows you to specify not only which IOS images to boot from, but also the order to try them in if it has trouble booting.

In the example, this router will try a succession of three different IOS images. If they all fail, it will resort to using its boot ROM image.

As we noted earlier, the sequence of the boot system commands is important since the router will attempt to load the IOS images in order of entry. This means that the only way to add a new IOS image to load is to remove all of the old boot system commands and reenter them again in the order of preference. You can remove all of the boot system commands at once with the following command:

Once the old boot system commands have been removed, you can configure a new set in whatever order you require.

In addition to allowing you to boot from IOS images in the router’s flash storage, you can also use the the boot system to boot from the IOS image in its ROM storage, or even using the TFTP or Remote Copy (RCP) protocols across the network. Recipe 1.8 shows an example of booting across the network, using TFTP. Table 1-1 shows all of the different options for the boot system command.

Table 1-1. Boot system command target options

Keyword	Description
flash:	On-board flash
slot0:	PCMCIA flash card in slot0
slot1:	PCMCIA flash card in slot1
mop:	Load an image using the MOP protocol
bootflash:	Load bootflash image (not available on all systems)
rom:	Load the image from ROM
rcp:	Load an image using the remote copy protocol
tftp:	Load an image using the TFTP protocol
ftp:	Load an image using the FTP protocol

In addition to the boot system commands, you can change which image the router will boot from using the router’s configuration register. The last octet in the configuration register must be set to 2 , or the router will ignore the boot system commands completely. For instance, if the last octet of the configuration register is set to 1 , the router will boot from ROM and ignore the boot system commands. In our example, the test router’s configuration register was set to 0x2102 . The config-register command allows you to set the appropriate configuration register values:

It is important to remember that unlike any other configuration command, you don’t need to save the running configuration to NVRAM when you change the configuration register setting. It will survive a reload without being saved. In fact, the new setting will not take effect until after the next reload:

After setting the appropriate boot system commands and reloading the router, you can see which image file the router used to boot with the show version command:

In this case, the router says that it loaded its IOS image from slot0: , as configured. After changing your boot system commands, you should be sure to reboot and verify that it behaved as expected. You don’t want the wrong IOS image to accidentally get loaded the next time the router reboots. If you do have problems with the boot system command, connect to the console and reload the router. This will display any error messages as the router boots. The router does not capture these messages anywhere, so this is the only way to see them.

Beginning with IOS Version 12.3(4)T, Cisco introduced the concept of boot markers. Essentially, all boot system command lines are now placed between two permanent boot markers located within the configuration file. These markers cannot be erased and make locating the boot system commands easy. The following is an example of a router using boot markers:

Notice that all of the boot system commands have been automatically placed between the start boot marker and the end boot marker. The files are also listed in order of boot preference. If you don’t configure the router with explicit boot system commands, then the router will load the first available IOS image in flash by default. In this case, the boot markers will still appear in the configuration file, but no boot system commands will accompany them:

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boot-start-marker

Hello, please I would like to know to me so that this command serves.

I’m sorry for my bad english.

RE: boot-start-marker

Boot-start-marker it is just a flag (marker) not a command. That flag helps the router to load the correct images using the boot statement commands. You can not change nor modify this flag, same applies to boot-end-marker. Cheers.

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Cisco IOS Boot System Image

When you power on a Cisco IOS router, it will take the following steps:

1. Perform a POST (Power on self test) to discover the hardware and to check if the hardware is working properly.
2. Copy a bootstrap program from ROM into the RAM, run the bootstrap program.
3. The bootstrap program looks for the first IOS image on the flash memory, extracts it into RAM and boots the IOS image. When there is no IOS image, it will boot into ROMMON.
4. When IOS has loaded, it will look for the startup-config file on the NVRAM. If there is none, it will show you a wizard asking you if you want to configure the router.

There is nothing we can change in step 1 and 2 but we are able to make some changes to step 3 and 4. It’s possible to configure the router so that it will look for an IOS image in another location, like a TFTP server on your network. You can also configure the router so that it looks for the startup-config somewhere else.

Let’s see how we can configure the router to boot another IOS image.

Default Boot Option

Which IOS image the router wants to use depends on two options:

• The configuration-register boot option.
• the boot system command

The default value of the configuration register is 0x2101:

You can find the meaning of the bits in this Cisco document. The first 4 bits define where the router will look for the IOS image. The default value is 0001 which means that it will use the first IOS image that it finds on the flash memory.

Let’s see what is on our flash memory:

There are two images. Cisco IOS uses a number for each filename and will prefer the lowest file number. We can see which image was booted:

Booting IOS image from flash

Let’s see how I can select a different image. I can configure the router to boot the other IOS image on my flash memory with the boot system command:

After reloading the router, I can verify that it has booted the newer image:

Booting IOS image from network

What if I want to boot an IOS image from the network? This could be useful. Perhaps your flash memory is too small to fit the latest IOS image or maybe you want to make sure all routers run the same IOS image without manually copying the images to the flash memory of each router.

The boot system command has some options:

One of the options is a TFTP server. Let’s see if we can boot from a TFTP server:

This tells the router to look for the specified filename on the TFTP server with IP address 192.168.1.2.

The command above however is only half of the story. The default configuration register will only look for the IOS image on the flash memory. We have to change it to tell the router to look for the IOS image on the network:

This tells the router to look for an IOS image on the network, not on the local flash drive. We also have to make sure the router is able to reach our TFTP server. Let’s enable an interface with an IP address that is in the same subnet as our TFTP server:

Now we can save our configuration and reload the router. Once you do, you will see this:

The router does its POST, initializes ROMMON and then loads the IOS image on the flash memory as usual. Once it is loaded, instead of showing you the command prompt you will see this:

It downloads the IOS image that we specified from the TFTP server. Once the transfer is completed, it extracts and loads the image:

Your router will now run the IOS image from the TFTP server.

Booting IOS image from network through ROMMON

What if your flash memory is defective but you still want to run IOS somehow? It is possible with ROMMON to download the image and then extract and run it in RAM, without touching your flash memory. When the router boots, hit the CTRL+BREAK combination to get into ROMMON:

Here we have to configure some variables. If your TFTP server is in the same subnet then you can skip the default gateway:

When you are ready, use the tftpdnld command with the -r parameter. This tells the router not to store the IOS image on the flash memory:

You will see a quick overview with your variables and the router will start downloading:

When it has received the file, it will extract it and load the IOS image in RAM. The router will then boot as normal.

Cisco IOS Configuration Fundamentals Command Reference

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Cisco IOS Configuration Fundamentals Command Reference

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activation-character

To define the character you ent er at a vacant terminal to begin a terminal session, use the activation-character command in line configuration mode. To make any character activate a terminal, use the no form of this command.

Syntax Description

Decimal representation of the activation character.

Command Default

Return (decimal 13)

Command Modes

Line configuration (config-line)

Command History

This command was introduced.

This command is supported in all Cisco IOS software Releases.

Usage Guidelines

See the “ASCII Character Set and Hexadecimal Values” document for a list of ASCII characters.

If you are using the autoselect function, set the activation character to the default, Return, and exec-character-bits to 7. If you change these defaults, the application will not recognize the activation request.

Examples

The following example shows how to set the activation character for the console to Delete, which is decimal character 127:

alias

To create a command alias, use the alias command in global configuration mode. To delete all aliases in a command mode or to delete a specific alias, and to revert to the original command syntax, use the no form of this command.

alias mode command-alias original-command

no alias mode [command-alias]

Syntax Description

Command mode of the original and alias commands.

Original command syntax.

Command Default

A set of six basic EXEC mode aliases are enabled by default. See the “Usage Guidelines” section of this command for a list of default aliases.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

The command alias ip-vrf has been replaced with alias vrf-af .

Usage Guidelines

You can use simple words or abbreviations as command aliases.

The table below lists the basic EXEC mode aliases that are enabled by default.

The default aliases in the table above are predefined. These default aliases can be disabled with the no alias exec command.

Common keyword aliases (which cannot be disabled) include running-config (keyword alias for system:running-config ) and startup-config (keyword alias for nvram:startup-config ). See the description of the copy command for more information about these keyword aliases.

Note that aliases can be configured for keywords instead of entire commands. You can create, for example, an alias for the first part of any command and still enter the additional keywords and arguments as normal.

To determine the value for the mode argument, enter the command mode in which you would issue the original command (and in which you will issue the alias) and enter the ? command. The name of the command mode should appear at the top of the list of commands. For example, the second line in the following sample output shows the name of the command mode as “Interface configuration”:

To match the name of the command mode to the acceptable mode keyword for the alias command, issue the alias ? command. As shown in the following sample output, the keyword needed to create a command alias for the access-expression command is interface :

When you use online help, command aliases are indicated by an asterisk (*), and displayed in the following format:

For example, the lo command alias is shown here along with other EXEC mode commands that start with “lo”:

When you use online help, aliases that contain multiple keyword elements separated by spaces are displayed in quotes, as shown here:

To list only commands and omit aliases, begin your input line with a space. In the following example, the alias td is not shown, because there is a space before the t? command line.

To circumvent command aliases, use a space before entering the command. In the following example, the command alias express is not recognized because a space is used before the command.

As with commands, you can use online help to display the arguments and keywords that can follow a command alias. In the following example, the alias td is created to represent the command telnet device . The /debug and /line switches can be added to telnet device to modify the command:

You must enter the complete syntax for the command alias. Partial syntax for aliases is not accepted. In the following example, the parser does not recognize the command t as indicating the alias td :

Examples

In the following example, the alias fixmyrt is configured for the clear iproute 192.168.116.16 EXEC mode command:

In the following example, the alias express is configured for the first part of the access-expression interface configuration command:

Related Commands

Displays command aliases.

archive

To enter archive configuration mode, use the archive command in global configuration mode.

Syntax Description

This command has no arguments or keywords.

Command Default

Archive configuration mode is not entered.

Command Modes

Global configuration (config)

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(25)S.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

This command was integrated into Cisco IOS Release 12.2(33)SB and implemented on the Cisco 10000 series.

Cisco IOS XE Release 3.9S

This command was integrated into Cisco IOS XE Release 3.9S.

Examples

The following example shows how to place the device in archive configuration mode:

Related Commands

Enters configuration change logger configuration mode.

Enables the logging of configuration changes.

Sets the maximum number of archive files of the running configuration to be saved in the Cisco configuration archive.

Specifies the location and filename prefix for the files in the Cisco configuration archive.

Sets the time increment for automatically saving an archive file of the current running configuration in the Cisco configuration archive.

archive config

To save a copy of the current running configuration to the Cisco configuration archive, use the archive config command in privileged EXEC mode.

Syntax Description

This command has no arguments or keywords.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(25)S.

This command was integrated into Cisco IOS Release 12.2(28)SB.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

This command was implemented on the Cisco 10000 series.

This command was integrated into Cisco IOS Release 12.2(33)SXH.

This command was integrated into Cisco IOS Release 12.2(33)SB and implemented on the Cisco 10000 series.

Cisco IOS XE Release 3.9S

This command was integrated into Cisco IOS XE Release 3.9S.

Usage Guidelines

Before using this command, you must configure the path command in order to specify the location and filename prefix for the files in the Cisco configuration archive.

The Cisco configuration archive is intended to provide a mechanism to store, organize, and manage an archive of Cisco configuration files to enhance the configuration rollback capability provided by the configure replace command. Before this feature was introduced, you could save copies of the running configuration using the copy running-config destination-url command, storing the target file either locally or remotely. However, this method lacked any automated file management. On the other hand, the Configuration Replace and Configuration Rollback feature provides the capability to automatically save copies of the running configuration to the Cisco configuration archive. These archived files serve as checkpoint configuration references and can be used by the configure replace command to revert to previous configuration states.

The archive config command allows you to save Cisco configurations in the configuration archive using a standard location and filename prefix that is automatically appended with an incremental version number (and optional time stamp) as each consecutive file is saved. This functionality provides a means for consistent identification of saved Cisco configuration files. You can specify how many versions of the running configuration are kept in the archive. After the maximum number of files has been saved in the archive, the oldest file is automatically deleted when the next, most recent file is saved. The show archive command displays information for all configuration files saved in the Cisco configuration archive.

Examples

The following example shows how to save the current running configuration to the Cisco configuration archive using the archive config command. Before using the archive config command, you must configure the path command to specify the location and filename prefix for the files in the Cisco IOS configuration archive. In this example, the location and filename prefix are specified as disk0:myconfig as follows:

You then save the current running configuration in the configuration archive, as follows:

The show archive command displays information on the files saved in the configuration archive as shown in the following sample output:

Related Commands

Enters archive configuration mode.

Confirms replacement of the current running configuration with a saved Cisco configuration file.

Replaces the current running configuration with a saved configuration file.

Sets the maximum number of archive files of the running configuration to be saved in the Cisco configuration archive.

Specifies the location and filename prefix for the files in the Cisco configuration archive.

Displays information about the files saved in the Cisco configuration archive.

Sets the time increment for automatically saving an archive file of the current running configuration in the Cisco configuration archive.

archive log config persistent save

To save the persisted commands in the configuration log to the Cisco IOS secure file system, use the archive log config persistent save command in privileged EXEC mode.

archive log config persistent save

Syntax Description

This command has no arguments or keywords.

Command Default

If this command is not entered, the persisted configuration commands in the archive log are not saved to the Cisco IOS secure file system.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.4(11)T.

This command was integrated into Cisco IOS Release 12.2(33)SXH.

This command was integrated into Cisco IOS Release 12.2(33)SB.

Usage Guidelines

If the router is in the persistent periodic mode, the persistent timer is restarted.

Examples

The following example saves the persisted commands in the archive log to the Cisco IOS secure file system:

Related Commands

Enters configuration change logger configuration mode.

Enables the logging of configuration changes.

Enables the configuration logging persistent feature.

archive tar

To create a TAR file, to list files in a TAR file, or to extract the files from a TAR file, use the archive tar command in privileged EXEC mode.

Syntax Description

/create destination-url flash:/ file-url

Creates a new TAR file on the local or network file system.

For destination-url , specify the destination URL alias for the local or network file system and the name of the TAR file to create. The following options are supported:

flash: —Syntax for the local flash file system.

ftp: [[ // username [ : password ] @ location ] / directory ] / tar-filename.tar — Syntax for FTP.

rcp: [[ // username @ location ] / directory ] / tar-filename.tar —Syntax for Remote Copy Protocol (RCP).

tftp: [[ // location ] / directory ] / tar-filename.tar —Syntax for TFTP.

The tar-filename.tar is the name of the TAR file to be created.

For flash:/ file-url , specify the location on the local flash file system from which the new TAR file is created.

An optional list of files or directories within the source directory can be specified to write to the new TAR file. If none is specified, all files and directories at this level are written to the newly created TAR file.

Display the contents of an existing TAR file to the screen.

For source-url , specify the source URL alias for the local or network file system. The following options are supported:

flash: —Syntax for the local flash file system.

ftp: [[ // username [ : password ] @ location ] / directory ] / tar-filename.tar — Syntax for FTP.

rcp: [[ // username @ location ] / directory ] / tar-filename.tar —Syntax for Remote Copy Protocol (RCP).

tftp: [[ // location ] / directory ] / tar-filename.tar —Syntax for TFTP.

The tar-filename.tar is the name of the TAR file to be created.

/xtract source-url flash:/ file-url [ dir/file . ]

Extracts files from a TAR file to the local file system.

For source-url , specify the source URL alias for the local file system. These options are supported:

flash: —Syntax for the local flash file system.

ftp: [[ // username [ : password ] @ location ] / directory ] / tar-filename.tar — Syntax for FTP.

rcp: [[ // username @ location ] / directory ] / tar-filename.tar —Syntax for Remote Copy Protocol (RCP).

tftp: [[ // location ] /directory ]/ tar-filename.tar —Syntax for TFTP.

The tar-filename.tar is the name of the TAR file to be created.

Command Default

The TAR archive file is not created.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SXH.

This command was integrated into Cisco IOS Release 12.4(22)YB.

This command was integrated into Cisco IOS Release 12.4(24)T.

Usage Guidelines

Filenames, directory names, and image names are case sensitive.

The TAR file is an archive file from which you can extract files by using the archive tar command.

Examples

The following example shows how to create a TAR file. The command writes the contents of the new-configs directory on the local flash device to a file named saved.tar on the TFTP server at 172.20.136.9.

The following example shows how to display the contents of the c2940-tv0-m.tar file that is in flash memory. The contents of the TAR file appear on the screen.

The following example shows how to extract the contents of a TAR file on the TFTP server at 172.20.10.30. This command extracts only the new-configs directory into the root directory on the local flash file system. The remaining files in the saved.tar file are ignored.

async-bootp

To configure extended BOOTP requests for asynchronous interfaces as defined in RFC 1084, use the async-bootp command in global configuration mode. To restore the default, use the no form of this command.

async-bootp tag [ : hostname ] data

Syntax Description

Item being requested; expressed as filename, integer, or IP dotted decimal address. See the table below for possible keywords.

(Optional) This entry applies only to the specified host. The :hostname argument accepts both an IP address and a logical host name.

List of IP addresses entered in dotted decimal notation or as logical host names, a number, or a quoted string.

Specifies use of a server boot file from which to download the boot program. Use the optional : hostname argument and the data argument to specify the filename.

Dotted decimal address specifying the network and local subnetwork mask (as defined by RFC 950).

Signed 32-bit integer specifying the time offset of the local subnetwork in seconds from Coordinated Universal Time (UTC).

Dotted decimal address specifying the IP addresses of gateways for this subnetwork. A preferred gateway should be listed first.

Dotted decimal address specifying the IP address of time servers (as defined by RFC 868).

Dotted decimal address specifying the IP address of name servers (as defined by IEN 116).

Dotted decimal address specifying the IP address of Windows NT servers.

Dotted decimal address specifying the IP address of domain name servers (as defined by RFC 1034).

Dotted decimal address specifying the IP address of an MIT-LCS UDP log server.

Dotted decimal address specifying the IP address of Quote of the Day servers (as defined in RFC 865).

Dotted decimal address specifying the IP address of Berkeley UNIX Version 4 BSD servers.

Dotted decimal address specifying the IP address of Impress network image servers.

Dotted decimal address specifying the IP address of Resource Location Protocol (RLP) servers (as defined in RFC 887).

The name of the client, which may or may not be domain qualified, depending upon the site.

A two-octet value specifying the number of 512-octet (byte) blocks in the default boot file.

Command Default

If no extended BOOTP commands are entered, the Cisco IOS software generates a gateway and subnet mask appropriate for the local network.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

Use the show async-bootp EXEC command to list the configured parameters. Use the no async-bootp command to clear the list.

Examples

The following example illustrates how to specify different boot files: one for a PC, and one for a Macintosh. With this configuration, a BOOTP request from the host on 172.30.1.1 results in a reply listing the boot filename as pcboot. A BOOTP request from the host named “mac” results in a reply listing the boot filename as “macboot.”

The following example specifies a subnet mask of 255.255.0.0:

The following example specifies a negative time offset of the local subnetwork of 3600 seconds:

The following example specifies the IP address of a time server:

Related Commands

show async bootp

Displays the extended BOOTP request parameters that have been configured for asynchronous interfaces.

attach

To connect to a specific line card or module from a remote location for the purpose of executing monitoring and maintenance commands on that line card or module, use the attach command in privileged EXEC mode. To exit from the Cisco IOS software image on the line card and return to the Cisco IOS image on the main (Supervisor) module, use the exit command.

Cisco 12000 Series

Cisco 7600 Series and Catalyst 6500 Series

Syntax Description

Slot number of the line card to which you wish to connect.

If you omit the slot number, you will be prompted for it.

Module number; see the “Usage Guidelines” section for valid values.

Command Default

No default behavior or values.

Command Modes

Command History

This command was introduced on the Cisco 12000 series.

This command was implemented on the Supervisor Engine 720.

Support was added for the Supervisor Engine 2.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

Cisco 12000 Series

You must first use the attach privileged EXEC command to access the Cisco IOS software image on a line card before using line card-specific show EXEC commands. Alternatively, you can use the execute-on privileged EXEC command to execute a show command on a specific line card.

After you connect to the Cisco IOS image on the line card using the attach command, the prompt changes to LC-Slotx# , where x is the slot number of the line card.

The commands executed on the line card use the Cisco IOS image on that line card.

You can also use the execute-on slot privileged EXEC command to execute commands on one or all line cards.

Do not execute the config EXEC command from the Cisco IOS software image on the line card.

Cisco 7600 Series and Catalyst 6500 Series

After you enter the attach or remote login command to access another console from your switch, if you enter global or interface configuration mode commands, the switch might reset.

Th e v alid values for the module-number argument depend on the chassis that is used. For example, if you have a 13-slot chassis, valid values for the module number are from 1 to 13.

This command is supported on Distributed Forwarding Card (DFC)-equipped modules, FlexWan modules, and the supervisor engine only.

When you execute the attach module-number command, the prompt changes to Router-dfcx# or Switch-sp#, depending on the type of module to which you are connecting.

The behavior of the attach command is identical to that of the remote login module num command.

There are two ways to end this session:

You can enter the exit command as follows:

You can press Ctrl-C three times as follows:

Examples

In the following example, the user connects to the Cisco IOS image running on the line card in slot 9, gets a list of valid show commands, and returns the Cisco IOS image running on the GRP:

Because not all statistics are maintained on line cards, the output from some of show commands may be inconsistent.

The following example shows how to log in remotely to the DFC-equipped module:

Related Commands

Connects you to a specific (managed) shelf for the purpose of remotely executing commands on that shelf only.

Executes commands remotely on a specific line card, or on all line cards simultaneously.

Accesses the Cisco 7600 series router console or a specific module.

autobaud

To set the line for automatic baud rate detection (autobaud), use the autobaud command in line configuration mode. To disable automatic baud detection, use the no form of this command.

Syntax Description

This command has no arguments or keywords.

Command Default

Autobaud detection is disabled. Fixed speed of 9600 bps.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

The autobaud detection supports a range from 300 to 19200 baud. A line set for autobaud cannot be used for outgoing connections, nor can you set autobaud capability on a line using 19200 baud when the parity bit is set (because of hardware limitations).

Automatic baud detection must be disabled by using the no autobaud command prior to setting the txspeed, rxspeed, or speed commands.

Examples

In the following example, the auxiliary port is configured for autobaud detection:

auto-sync

To enable automatic synchronization of the configuration files in NVRAM, use the auto-sync command in main-cpu redundancy configuration mode. To disable automatic synchronization, use the no form of this command.

Syntax Description

Specifies synchronization of the startup configuration files.

Specifies synchronization of the configuration register values.

Specifies synchronization of the following boot variables:

BOOT—Set by the boot system device:filename command.

CONFIG_FILE—Set by the boot config device:filename command.

BOOTLDR—Set by the boot bootldr device:filename command.

Specifies synchronization of the running configuration files.

Specifies synchronization of all of the system files (startup configuration, boot variables, and config configuration registers).

Command Default

For the Performance Routing Engines (PREs) on the Cisco uBR10012 universal broadband router, the system defaults to synchronizing all system files on the ( auto-sync standard ).

For the Supervisor Engines on the Cisco 7600 series routers, the system defaults to synchronizing the running configuration. ( running-config ).

At the Cisco RF Gateway 10 chassis level, all the system files are synchronized by default.

Cisco RF Gateway 10

Redundancy configuration (config-r)

Main CPU redundancy configuration (config-r-mc)

Command History

This command was introduced on the Cisco uBR10012 universal broadband router.

This command was integrated into the Supervisor Engine 720.

Support was added for the Supervisor Engine 2.

Support for this command on the Cisco 7600 series routers was removed.

This command was integrated into Cisco IOS Release 12.3BC for the Cisco uBR10012 router.

This command is obsolete on the Cisco uBR10012 universal broadband router.

This command was integrated into Cisco IOS Release 12.2(44)SQ. Support for the Cisco RF Gateway 10 was added.

Usage Guidelines

Cisco 7600 Series Routers

If you enter the no auto-sync standard command, no automatic synchronizations occur. If you want to enable any of the keywords, you have to enter the appropriate command for each keyword.

The auto-sync command is not supported in RPR+ mode.

Cisco uBR10012 Universal Broadband Router

By default, the system synchronizes all system files, which is the typical setting for most applications. However, you might want exclude certain files from synchronization for specialized applications.

For example, if you have configured the active and standby PRE1 (or PRE2) modules to run different versions of Cisco IOS software, you might want to use different configuration files as well. In this case, you would not synchronize the startup configuration file.

Cisco RF Gateway 10

We recommend that you use the auto-sync standard command to ensure that all system files are synchronized between the two Supervisor modules. The no auto-sync command is not used in production plants.

Examples

Examples

The following example shows how (from the default configuration) to enable automatic synchronization of the configuration register in the main CPU:

Examples

The following example shows the system being configured to synchronize only the startup configuration file:

The following example shows how to configure the system to synchronize all system files except for the startup configuration file. This typically is done when the two PRE1 (or PRE2) modules are running different software images.

Examples

The following example shows the synchronization of all system files on the Cisco RFGW-10 chassis:

Related Commands

Enters redundancy configuration mode.

Enters main CPU redundancy configuration mode.

autoupgrade disk-cleanup

To configure the Cisco IOS Auto-Upgrade Manager disk cleanup utility, use the autoupgrade disk-cleanup command in global configuration mode. To disable this configuration, use the no form of this command.

autoupgrade disk-cleanup [ crashinfo | core | image | irrecoverable ]

no autoupgrade disk-cleanup [ crashinfo | core | image | irrecoverable ]

Syntax Description

(Optional) Deletes crashinfo files during disk-cleanup before an image is downloaded.

(Optional) Deletes core files during disk-cleanup before an image is downloaded.

(Optional) Deletes the Cisco IOS images, except the default boot image and the current image, during disk-cleanup before an image is downloaded.

(Optional) Deletes files irretrievably (in a file-system that supports the undelete operation) during disk-cleanup before an image is downloaded.

Command Default

By default, the crashinfo files, the core files, and the Cisco software images are deleted by the Cisco IOS Auto-Upgrade Manager disk cleanup utility, and the filesystems that support the undelete operation are not cleaned up.

Command Modes

Global configuration (config)

Command History

This command was introduced.

Cisco IOS XE Release 3.9S

This command was integrated into Cisco IOS XE Release 3.9S.

Examples

The following example shows how to clean-up filesystems that support undelete operation:

The following example shows how to avoid deleting the Cisco software images:

Related Commands

autoupgrade ida url

Configures the URL of the server on www.cisco.com where the image download requests will be sent by the Cisco IOS Auto-Upgrade Manager.

autoupgrade status email

Configures the address to which the status email is to be sent.

upgrade automatic getversion

Downloads a Cisco software image directly from www.cisco.com or from a non-Cisco server.

autoupgrade ida url

To configure the URL of the Intelligent Download Application (IDA) running on www.cisco.com, use the autoupgrade ida url command in global configuration mode. To disable this URL, use the no form of this command.

autoupgrade ida url url

no autoupgrade ida url url

Syntax Description

URL of the IDA server.

Command Default

Default URL: https://www.cisco.com/cgi-bin/ida/locator/locator.pl

Command Modes

Global configuration (config)

Command History

This command was introduced.

Cisco IOS XE Release 3.9S

This command was integrated into Cisco IOS XE Release 3.9S.

Usage Guidelines

Use the autoupgrade ida url command to configure a new URL for the IDA server, if it is not present in the default location. The device sends the image download requests to the configured URL.

Examples

The following example shows how to configure the URL for the IDA server:

Related Commands

Configures the Cisco IOS Auto-Upgrade Manager disk cleanup utility.

autoupgrade status email

Configures the address to which the status email is to be sent.

upgrade automatic getversion

Downloads a Cisco software image directly from www.cisco.com or from a non-Cisco server.

autoupgrade status email

To configure the address to which status email is to be sent and the outgoing email server, use the autoupgrade status email command in global configuration mode. To disable status email, use the no form of this command.

autoupgrade status email [ recipient [email-address] ] [ smtp-server [smtp-server] ]

no autoupgrade status email [ recipient [email-address] ] [ smtp-server [smtp-server] ]

Syntax Description

The address to which the Cisco IOS Auto-Upgrade Manager (AUM) status is to be sent.

The outgoing email server to which the AUM email is sent.

The email address to which the AUM status is to be sent.

Command Default

Status email is not sent unless the address is configured. The recipient email address and SMTP server have to be configured in order to receive AUM status email.

Command Modes

Global configuration (config)

Command History

This command was introduced.

Cisco IOS XE Release 3.9S

This command was integrated into Cisco IOS XE Release 3.9S.

Usage Guidelines

Use this command to configure the email-address where AUM status email can be sent.

Examples

The following example shows how to configure the address to which status email is to be sent:

Related Commands

Configures the Cisco IOS Auto-Upgrade Manager disk cleanup utility.

autoupgrade ida url

Configures the URL of the server running on www.cisco.com to which the device sends the image download requests.

upgrade automatic getversion

Downloads a Cisco software image directly from www.cisco.com or from a non-Cisco server.

banner exec

To specify and enable a message to be displayed when an EXEC process is created (an EXEC banner), use the banner exec command in global configuration mode. To delete the existing EXEC banner, use the no form of this command.

banner exec d message d

Syntax Description

Delimiting character of your choice—a pound sign (#), for example. You cannot use the delimiting character in the banner message.

Message text. You can include tokens in the form $(token ) in the message text. Tokens will be replaced with the corresponding configuration variable. Tokens are described in the table below.

Command Default

Disabled (no EXEC banner is displayed).

Command Modes

Command History

This command was introduced.

Token functionality was introduced.

Token functionality was integrated into Cisco IOS Release 12.0(3)T.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

This command specifies a message to be displayed when an EXEC process is created (a line is activated, or an incoming connection is made to a vty). Follow this command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.

When a user connects to a router, the message-of-the-day (MOTD) banner appears first, followed by the login banner and prompts. After the user logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection. For a reverse Telnet login, the incoming banner will be displayed. For all other connections, the router will display the EXEC banner.

To disable the EXEC banner on a particular line or lines, use the no exec-banner line configuration command.

To customize the banner, use tokens in the form $(token ) in the message text. Tokens will display current Cisco IOS configuration variables, such as the router’s host name and IP address. The tokens are described in the table below.

Information Displayed in the Banner

Displays the host name for the router.

Displays the domain name for the router.

Displays the vty or tty (asynchronous) line number.

Displays the description attached to the line.

Examples

The following example sets an EXEC banner that uses tokens. The percent sign (%) is used as a delimiting character. Notice that the $(token ) syntax is replaced by the corresponding configuration variable.

When a user logs on to the system, the following output is displayed:

Related Commands

Defines a customized banner to be displayed when there is an incoming connection to a terminal line from a host on the network.

Defines a customized banner to be displayed before the username and password login prompts.

Defines a customized message-of-the-day banner.

Defines a customized banner to be displayed when a serial-line IP or point-to-point connection is made.

Controls (enables or disables) the display of EXEC banners and message-of-the-day banners on a specified line or lines.

banner incoming

To define and enable a banner to be displayed when there is an incoming connection to a terminal line from a host on the network, use the banner incoming command in global configuration mode. To delete the incoming connection banner, use the no form of this command.

banner incoming d message d

no banner incoming

Syntax Description

Delimiting character of your choice—a pound sign (#), for example. You cannot use the delimiting character in the banner message.

Message text. You can include tokens in the form $(token ) in the message text. Tokens will be replaced with the corresponding configuration variable. Tokens are described in the table below.

Command Default

Disabled (no incoming banner is displayed).

Command Modes

Command History

This command was introduced.

Token functionality was introduced.

Token functionality was integrated into Cisco IOS Release 12.0(3)T.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

Follow the banner incoming command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.

An incoming connection is one initiated from the network side of the router. Incoming connections are also called reverse Telnet sessions. These sessions can display MOTD banners and incoming banners, but they do not display EXEC banners. Use the no motd-banner line configuration command to disable the MOTD banner for reverse Telnet sessions on asynchronous lines.

When a user connects to the router, the message-of-the-day (MOTD) banner (if configured) appears first, before the login prompt. After the user successfully logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection. For a reverse Telnet login, the incoming banner will be displayed. For all other connections, the router will display the EXEC banner.

Incoming banners cannot be suppressed. If you do not want the incoming banner to appear, you must delete it with the no banner incoming command.

To customize the banner, use tokens in the form $(token ) in the message text. Tokens will display current Cisco IOS configuration variables, such as the router’s host name and IP address. The tokens are described in the table below.

Information Displayed in the Banner

Displays the host name for the router.

Displays the domain name for the router.

Displays the vty or tty (asynchronous) line number.

Displays the description attached to the line.

Examples

The following example sets an incoming connection banner. The pound sign (#) is used as a delimiting character.

The following example sets an incoming connection banner that uses several tokens. The percent sign (%) is used as a delimiting character.

When the incoming connection banner is executed, the user will see the following banner. Notice that the $(token ) syntax is replaced by the corresponding configuration variable.

Related Commands

Defines a customized banner to be displayed whenever the EXEC process is initiated.

Defines a customized banner to be displayed before the username and password login prompts.

Defines a customized message-of-the-day banner.

Defines a customized banner to be displayed when a serial-line IP or point-to-point connection is made.

banner login

To define and enable a customized banner to be displayed before the username and password login prompts, use the banner login command in global configuration mode. To disable the login banner, use no form of this command.

banner login d message d

no banner login

Syntax Description

Delimiting character of your choice—a pound sign (#), for example. You cannot use the delimiting character in the banner message.

Message text. You can include tokens in the form $(token) in the message text. Tokens will be replaced with the corresponding configuration variable. Tokens are described in the table below.

Command Default

Disabled (no login banner is displayed).

Command Modes

Command History

This command was introduced.

Token functionality was introduced.

Token functionality was integrated into Cisco IOS Release 12.0(3)T.

This command was integrated into Cisco IOS Release 12.2(14)SX.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

Follow the banner login command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.

When a user connects to the router, the message-of-the-day (MOTD) banner (if configured) appears first, followed by the login banner and prompts. After the user successfully logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection. For a reverse Telnet login, the incoming banner will be displayed. For all other connections, the router will display the EXEC banner.

To customize the banner, use tokens in the form $(token ) in the message text. Tokens will display current Cisco IOS configuration variables, such as the router’s host name and IP address. The tokens are described in the table below.

Information Displayed in the Banner

Displays the host name for the router.

Displays the domain name for the router.

Displays the vty or tty (asynchronous) line number.

Displays the description attached to the line.

Examples

The following example sets a login banner. Double quotes («) are used as the delimiting character.

The following example sets a login banner that uses several tokens. The percent sign (%) is used as the delimiting character.

When the login banner is executed, the user will see the following banner. Notice that the $(token) syntax is replaced by the corresponding configuration variable.

Related Commands

Defines a customized banner to be displayed whenever the EXEC process is initiated.

Defines a customized message to be displayed when there is an incoming connection to a terminal line from a host on the network.

Defines a customized message-of-the-day banner.

Defines a customized banner to be displayed when a serial-line IP or point-to-point connection is made.

banner motd

To define and enable a message-of-the-day (MOTD) banner, use the banner motd command in global configuration mode. To delete the MOTD banner, use the no form of this command.

banner motd d message d

Syntax Description

Delimiting character of your choice—a pound sign (#), for example. You cannot use the delimiting character in the banner message.

Message text. You can include tokens in the form $(token ) in the message text. Tokens will be replaced with the corresponding configuration variable.

Command Default

Disabled (no MOTD banner is displayed).

Command Modes

Command History

This command was introduced.

Token functionality was introduced.

Token functionality was integrated into Cisco IOS Release 12.0(3)T.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

Follow this command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.

This MOTD banner is displayed to all terminals connected and is useful for sending messages that affect all users (such as impending system shutdowns). Use the no exec-banner or no motd-banner command to disable the MOTD banner on a line. The no exec-banner command also disables the EXEC banner on the line.

When a user connects to the router, the MOTD banner appears before the login prompt. After the user logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection. For a reverse Telnet login, the incoming banner will be displayed. For all other connections, the router will display the EXEC banner.

To customize the banner, use tokens in the form $(token ) in the message text. Tokens will display current Cisco IOS configuration variables, such as the router’s host name and IP address. The tokens are described in the table below.

Information Displayed in the Banner

Displays the host name for the router.

Displays the domain name for the router.

Displays the vty or tty (asynchronous) line number.

Displays the description attached to the line.

Examples

The following example configures an MOTD banner. The pound sign (#) is used as a delimiting character.

The following example configures an MOTD banner with a token. The percent sign (%) is used as a delimiting character.

When the MOTD banner is executed, the user will see the following. Notice that the $(token ) syntax is replaced by the corresponding configuration variable.

Related Commands

Defines and enables a customized banner to be displayed whenever the EXEC process is initiated.

Defines and enables a customized message to be displayed when there is an incoming connection to a terminal line from a host on the network.

Defines and enables a customized banner to be displayed before the username and password login prompts.

Defines and enables a customized banner to be displayed when a serial-line IP or point-to-point connection is made.

Controls (enables or disables) the display of EXEC banners and message-of-the-day banners on a specified line or lines.

Controls (enables or disables) the display of message-of-the-day banners on a specified line or lines.

banner slip-ppp

To customize the banner that is displayed when a Serial Line Internet Protocol (SLIP) or PPP connection is made, use the banner slip-ppp command in global configuration mode. To restore the default SLIP or PPP banner, use the no form of this command.

banner slip-ppp d message d

no banner slip-ppp

Syntax Description

Delimiting character of your choice—a pound sign (#), for example. You cannot use the delimiting character in the banner message.

Message text. You can include tokens in the form $(token ) in the message text. Tokens will be replaced with the corresponding configuration variable.

Command Default

The default SLIP or PPP banner message is:

The banner message when using the service old-slip-prompt command is:

where encapsulation is SLIP or PPP.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

Follow this command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.

Use this command to define a custom SLIP or PPP connection message. This is useful when legacy client applications require a specialized connection string. To customize the banner, use tokens in the form $(token ) in the message text. Tokens will display current Cisco IOS configuration variables, such as the routers host name, IP address, encapsulation type, and Maximum Transfer Unit (MTU) size. The banner tokens are described in the table below.

Information Displayed in the Banner

Displays the host name of the router.

Displays the domain name of the router.

Displays the IP address of the peer machine.

Displays the IP address of the gateway machine.

Displays the encapsulation type (SLIP, PPP, and so on).

Displays the encapsulation type as SL/IP instead of SLIP.

Displays the MTU size.

Examples

The following example sets the SLIP/PPP banner using several tokens and the percent sign (%) as the delimiting character:

The new SLIP/PPP banner will now be displayed when the slip EXEC command is used. Notice that the $(token ) syntax is replaced by the corresponding configuration variable.

Related Commands

Defines and enables a customized banner to be displayed whenever the EXEC process is initiated.

Defines and enables a customized message to be displayed when there is an incoming connection to a terminal line from a host on the network.

Defines and enables a customized message-of-the-day banner.

Initiates a connection to a remote host using PPP.

Initiates a connection to a remote host using SLIP.

To boot the router manually, use the boot command in ROM monitor mode. The syntax of this command varies according to the platform and ROM monitor version.

boot filename [tftp-ip-address]

boot flash [ flash-fs : ] [ partition-number : ] [filename]

Cisco 7000 Series, 7200 Series, 7500 Series Routers

boot flash-fs : [filename]

Cisco 1600 and Cisco 3600 Series Routers

boot [ flash-fs : ] [ partition-number : ] [filename]

Cisco 1800 Series, 2800 Series, and 3800 Series Routers

boot usbflash0 [ : filename ]

Syntax Description

URL of the image to boot (for example, boot tftp://172.16.15.112/routertest ).

When used in conjunction with the ip-address argument, the filename argument is the name of the system image file to boot from a network server. The filename is case sensitive.

When used in conjunction with the flash keyword, the filename argument is the name of the system image file to boot from Flash memory.

On all platforms except the Cisco 1600 series, Cisco 3600 series, and Cisco 7000 family routers, the system obtains the image file from internal Flash memory.

On the Cisco 1600 series, Cisco 3600 series and Cisco 7000 family routers, the flash-fs : argument specifies the Flash memory device from which to obtain the system image. (See the flash-fs : argument later in this table for valid device values.) The filename is case sensitive. Without the filename argument , the first valid file in Flash memory is loaded.

If the filename is not specified, the first file in the partition or file system is used. (A USB Flash uses the first image in (compact) Flash as the boot loader and loads the image from USB Flash.)

(optional) IP address of the TFTP server on which the system image resides. If omitted, this value defaults to the IP broadcast address of 255.255.255.255.

Boots the router from Flash memory. Note that this keyword is required in some boot images.

Boot the first file in USB Flash 0. If the optional filename argument is used, the router boots the specified image from USB Flash.

This option uses the first image in (compact) Flash as the boot loader and loads the image from USB Flash.

(Optional) Specifying the Flash file system is optional for all platforms except the Cisco 7500 series routers. Possible file systems are:

flash: —Internal Flash memory.

bootflash: —Internal Flash memory on the Cisco 7000 family.

slot0: —Flash memory card in the first PCMCIA slot on the Cisco 7000 family and Cisco 3600 series routers.

slot1: —Flash memory card in the second PCMCIA slot on the Cisco 7000 family and Cisco 3600 series routers.

(Optional) Specifies the partition number of the file system the file should be loaded from. This argument is not available on all platforms. If the partition-number is not specified, the first partition is used.

Command Default

For most platforms, if you enter the boot command and press Enter, the router boots from ROM by default. However, for some platforms, such as the Cisco 3600 series routers, if you enter the boot command and press Enter, the router boots the first image in Flash memory. Refer to the documentation for your platform for information about the default image.

Command Modes

Command History

The command was introduced.

The usbflash0 keyword was added to support booting an image from an external USB Flash drive.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

To determine which form of this command to use, refer to the documentation for your platform or use the CLI help ( ? ) feature.

Use this command only when your router cannot find the boot configuration information needed in NVRAM. To enter ROM monitor mode, use one of the following methods:

Enter the reload EXEC command, then press the Break key during the first 60 seconds of startup.

Set the configuration register bits 0 to 3 to zero (for example, set the configuration register to 0x0) and enter the reload command.

The ROM Monitor prompt is either “>” or, for newer platforms, “rommon x >”. Enter only lowercase commands.

These commands work only if there is a valid image to boot. Also, from the ROM monitor prompt, issuing a prior reset command is necessary for the boot to be consistently successful.

In Cisco IOS Release 12.3(4)T, MONLIB was modified to search in media for a valid Cisco IOS image. This change prevents boot failures that result when the first file read in disk or flash is not a valid Cisco IOS image.

Refer to your hardware documentation for information on correct jumper settings for your platform.

For some platforms the flash keyword is now required. If your attempts to use the boot command are failing using the older boot flash: x : [filename ] syntax, try using the boot flash flash: x : [filename ] syntax.

Examples

In the following example, a router is manually booted from ROM:

In the following example, a router boots the file named routertest from a network server with the IP address 172.16.15.112 using the file-url syntax:

The following example shows the boot flash command without the filename argument. The first valid file in Flash memory is loaded.

The following example boots from Flash memory using the file named gs7-k:

In the following example, the boot flash flash: command boots the relocatable image file named igs-bpx-l from partition 2 in Flash memory:

In the following command, the Cisco 7000 family router accepts the flash keyword for compatibility but ignores it, and boots from slot 0:

In the following example, the command did not function because it must be entered in lowercase:

The following example boots the first file in the first partition of internal Flash memory of a Cisco 3600 series router:

The following example boots the first image file in the first partition of the Flash memory card in slot 0 of a Cisco 3600 series router:

The following example shows the ROM monitor booting the first file in the first Flash memory partition on a Cisco 1600 series router:

Related Commands

Returns to EXEC mode from ROM monitor mode by completing the boot process.

boot bootldr

To specify the location of the boot image that ROM uses for booting, use the boot bootldr command in global configuration mode. To remove this boot image specification, use the no form of this command.

boot bootldr file-url boot bootldr command

no boot bootldr

Syntax Description

URL of the boot image on a Flash file system.

Command Default

Refer to your platform documentation for the location of the default boot image.

Command Modes

Global configuration (config)

Command History

The command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

The boot bootldr command sets the BOOTLDR variable in the current running configuration. You must specify both the Flash file system and the filename.

When you use this global configuration command, you affect only the running configuration. You must save the variable setting to your startup configuration to place the information under ROM monitor control and to have the variable function as expected. Use the copy system:running-config nvram:startup-config command to save the variable from your running configuration to your startup configuration.

The default length of the bootstring filename is 64 characters. Depending on the platform a longer bootstring filename can be used and supported.

The no form of the command sets the BOOTLDR variable to a null string. On the Cisco 7000 family routers , a null string causes the first image file in boot Flash memory to be used as the boot image that ROM uses for booting.

Use the show boot command to display the current value for the BOOTLDR variable.

Examples

In the following example, the internal Flash memory contains the boot image:

The following example specifies that the Flash memory card inserted in slot 0 contains the boot image:

Related Commands

copy system:running-config nvram:startup-config

Copies any file from a source to a destination.

show (flash file system)

Displays the layout and contents of a Flash memory file system.

Displays the contents of the BOOT variable, the name of the configuration file pointed to by the CONFIG_FILE variable, the contents of the BOOTLDR variable, and the configuration register setting.

boot bootstrap

To configure the filename that is used to boot a secondary bootstrap image, use the boot bootstrap command in global configuration mode. To disable booting from a secondary bootstrap image, use the no form of this command.

boot bootstrap file-url

no boot bootstrap file-url

boot bootstrap flash [filename]

no boot bootstrap flash [filename]

boot bootstrap [ tftp ] filename [ip-address]

no boot bootstrap [ tftp ] filename [ip-address]

boot bootstrap mop filename [ interface-type interface-number ]

no boot bootstrap mop filename [ interface-type interface-number ]

Syntax Description

URL of the bootstrap image.

Boots the router from flash memory.

(Optional with flash ) Name of the system image to boot from a network server or from flash memory. If you omit the filename when booting from flash memory, the router uses the first system image stored in flash memory.

(Optional) Boots the router from a system image stored on a TFTP server.

(Optional) IP address of the TFTP server on which the system image resides. If the ip-address argument is omitted, this value defaults to the IP broadcast address of 255.255.255.255.

Boots the router from a DECnet Maintenance Operation Protocol (MOP) server.

(Optional) Interface type. For more information, use the question mark (?) online help function.

(Optional) Interface or subinterface number. For more information about the numbering syntax for your networking device, use the question mark (?) online help function.

Command Default

No secondary bootstrap is configured.

Command Modes

Global configuration (config)

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

This command was modified in a release earlier than Cisco IOS Release 15.0(1)M. The mop keyword and interface-type interface-number arguments were added.

This command was integrated into a release earlier than Cisco IOS Release 12.2(33)SXI.

Cisco IOS XE Release 2.1

This command was implemented on the Cisco ASR 1000 Series Aggregation Services Routers.

Usage Guidelines

The boot bootstrap command causes the router to load a secondary bootstrap image from the specied URL, such as from a remote server. After the bootstrap image is loaded, the bootstrap image loads the specified system image file. See the appropriate hardware installation guide for details on setting the configuration register and secondary bootstrap filename.

Use this command when you have attempted to load a system image but have run out of memory even after compressing the system image. Secondary bootstrap images allows you to load a larger system image through a smaller secondary image.

Examples

The following example shows how to load the system image file named sysimage-2 by using a secondary bootstrap image:

Related Commands

Boots the router manually.

Specifies the system image that the router loads at startup.

boot config

To s pecify the device and filename of the configuration file from which the system configures itself during initialization (startup), use the boot config command in global configuration mode. To return to the default location for the configuration file, use the no form of this command.

Platforms Other than Cisco 7600 Series Router

boot config file-system-prefix : [directory/] filename [ nvbypass ]

Cisco 7600 Series Router

boot config device : filename [ nvbypass ]

Syntax Description

File system, followed by a colon (for example, nvram: , flash: , slot0: , usbflash 0 9 : , or usbtoken 0 9 : ). The default is nvram: .

(Optional) File system directory where the configuration file is located, followed by a forward slash (/).

Name of the configuration file.

Device identification, followed by a colon; see the “Usage Guidelines” section for a list of the valid values.

(Optional) Specifies that the distilled configuration is not written to nonvolatile random access memory (NVRAM).

Command Default

The default location for the configuration file is NVRAM ( nvram: ).

Command Modes

Global configuration (config)

Supported Platforms Other than Cisco 7600 Series Router

Command History

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Support for this command was added for the Cisco 7600 Supervisor Engine 720.

Support for this command on the cisco 7600 Supervisor Engine 2 was extended to Release 12.2(17d)SXB.

This command was introduced.

Support for Class B file system platforms and the following file system prefix options were added: usbflash 0 9 : and usbtoken 0 9 :

This command is available only on Class A and Class B file system platforms.

You set the CONFIG_FILE environment variable in the current running memory when you use the boot config command. This variable specifies the configuration file used for initialization (startup). The configuration file must be an ASCII file located in either NVRAM or flash memory.

The valid values for the device : argument and colon are as follows:

For systems that are configured with a Supervisor Engine 2, the valid values are bootflash: , const_nvram: , flash: , nvram: , slot0: , sup-slot0: , and sup-bootflash:

For systems that are configured with a Supervisor Engine 720, the valid values are disk0: and disk1:

The configuration file must be an ASCII file that is located in the specified file system.

The disk0: and disk1: keywords are for Class C file systems.

The bootflash: , slot0: , and sup-bootflash: keywords are for Class A file systems.

For Class A flash file systems, the CONFIG_FILE environment variable specifies the file system and filename of the configuration file to use for initialization (startup). You set the CONFIG_FILE environment variable in the current running memory when you use the boot config command. This variable specifies the configuration file used for initialization (startup).

When you use the boot config command, you affect only the running configuration. You must save the environment variable setting to your startup configuration to place the information under ROM monitor control and to have the environment variable function as expected. Use the copy system:running-config nvram:startup-config command to save the environment variable from your running configuration to your startup configuration.

The software displays an error message and does not update the CONFIG_FILE environment variable in the following situations:

You specify nvram: as the file system, and it contains only a distilled version of the configuration. (A distilled configuration is one that does not contain access lists.)

You specify a configuration file in the filename argument that does not exist or is not valid.

The router uses the NVRAM configuration during initialization when the CONFIG_FILE environment variable does not exist or when it is null (such as at first-time startup). If the software detects a problem with NVRAM or the configuration it contains, the device enters setup mode.

When you use the no form of this command, the router returns to using the default NVRAM configuration file as the startup configuration.

You can display the contents of the BOOT, BOOTLDR, and the CONFIG_FILE environment variables using the show bootvar command. This command displays the settings for these variables as they exist in the startup configuration and in the running configuration if a running configuration setting differs from a startup configuration setting.

When the boot config command is used, the distilled configuration is written into NVRAM and the system configuration is written into the file specified by the boot config command. If the distilled configuration exceeds the size of NVRAM, the system configuration gets truncated. Use the nvbypass keyword to prevent the system configuration from being truncated when the distilled configuration is larger than the size of NVRAM.

Examples

The following example shows how to set the configuration file that is located in internal flash memory to configure itself during initialization. The third line copies the specification to the startup configuration, ensuring that this specification will take effect upon the next reload.

The following example instructs a Cisco 7500 series router to use the configuration file named router-config located on the flash memory card inserted in the second Personal Computer Memory Card Industry Association (PCMCIA) slot of the Route Switch Processor (RSP) card during initialization. The third line copies the specification to the startup configuration, ensuring that this specification will take effect upon the next reload.

Related Commands

copy system:running-config nvram:startup-config

Saves the environment variable from the running configuration to the startup configuration.

Displays the contents of the BOOT environment variable, the name of the configuration file pointed to by the CONFIG_FILE environment variable, the contents of the BOOTLDR environment variable, and the configuration register setting.

boot host

To specify the host-specific configuration file to be used at the next system startup, use the boot host command in global configuration mode. To restore the host configuration filename to the default, use the no form of this command.

boot host commandboot host remote-url

no boot host remote-url

Syntax Description

Location of the configuration file. Use the following syntax:

ftp: [[[ // [ username [ : password ] @ ] location ] / directory ] / filename ]

rcp: [[[ // [ username @ ] location ] / directory ] / filename ]

tftp: [[[ // location ] / directory ] / filename ]

Command Default

If you do not specify a filename using this command, the router uses its configured host name to request a configuration file from a remote server. To form the configuration filename, the router converts its name to all lowercase letters, removes all domain information, and appends -confg or -config.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

This command instructs the system to “Boot using host-specific configuration file x ,” where x is the filename specified in the remote-url argument. In other words, this command specifies the remote location and filename of the host-specific configuration file to be used at the next system startup, as well as the protocol to be used to obtain the file.

Before using the boot host command, use the service config global configuration command to enable the loading of the specified configuration file at reboot time. Without this command, the router ignores the boot host command and uses the configuration information in NVRAM. If the configuration information in NVRAM is invalid or missing, the service config command is enabled automatically.

The network server will attempt to load two configuration files from remote hosts. The first is the network configuration file containing commands that apply to all network servers on a network. Use the boot network command to identify the network configuration file. The second is the host configuration file containing commands that apply to one network server in particular. Use the boot host command to identify the host configuration file.

Usually, the service config command is used in conjunction with the boot host or boot network command. You must enter the service config command to enable the router to automatically configure the system from the file specified by the boot host or boot network command. With IOS software versions 12.3(2)T , 12.3(1)B, and later, you no longer have to specify the service config command for the boot host or boot network command to be active. If you specify both the no service config command and the boot host command, the router attempts to find the specified host configuration file. The service config command can also be used without the boot host or boot network command. If you do not specify host or network configuration filenames, the router uses the default configuration files. The default network configuration file is network-confg. The default host configuration file is host-confg, where host is the hostname of the router. If the Cisco IOS software cannot resolve its hostname, the default host configuration file is router-confg.

Loading a Configuration File Using rcp

The rcp software requires that a client send the remote username on each rcp request to the network server. If the server has a directory structure (such as UNIX systems), the rcp implementation searches for the configuration files starting in the directory associated with the remote username.

When you load a configuration file from a server using rcp, the Cisco IOS software sends the first valid username in the following list:

The username specified in the file-URL, if a username is specified.

The username set by the ip rcmd remote-username command, if the command is configured.

The router host name.

An account for the username must be defined on the destination server. If the network administrator of the destination server did not establish an account for the username, this command will not execute successfully.

Loading a Configuration File Using FTP

The FTP protocol requires a client to send a remote username and password on each FTP request to a server. The username and password must be associated with an account on the FTP server. If the server has a directory structure, the configuration file or image copied from the directory is associated with the username on the server. Refer to the documentation for your FTP server for more details.

When you load a configuration file from a server using FTP, the Cisco IOS software sends the first valid username in the following list:

The username specified in the boot host command, if a username is specified.

The username set by the ip ftp username command, if the command is configured.

The router sends the first valid password in the following list:

The password specified in the boot host command, if a password is specified.

The password set by the ip ftp password command, if the command is configured.

The router forms a password username @routername .domain . The variable username is the username associated with the current session, routername is the configured host name, and domain is the domain of the router.

Examples

The following example sets the host filename to wilma-confg at address 192.168.7.19:

Related Commands

Specifies the remote location and filename of the network configuration file to be used at the next system boot (startup).

Enables autoloading of configuration files from a network server.

boot network

To change the default name of the network configuration file from which to load configuration commands, use the boot network command in global configuration mode. To restore the network configuration filename to the default, use the no form of this command.

boot network remote-url

no boot network remote-url

Syntax Description

Location of the configuration file. Use the following syntax:

ftp: [[[ // [ username [ : password ] @ ] location ] / directory ] / filename ]

rcp: [[[ // [ username @ ] location ] / directory ] / filename ]

tftp: [[[ // location ] / directory ] / filename ]

Command Default

The default filename is network-config.

Command Modes

Command History

This command was introduced.

This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

This command instructs the system to “Boot using network configuration file x ,” where x is the filename specified in the remote-url argument. This command specifies the remote location and filename of the network configuration file to be used at the next system startup, as well as the protocol to be used to obtain the file.

When booting from a network server, routers ignore routing information, static IP routes, and bridging information. As a result, intermediate routers are responsible for handling FTP, rcp, or TFTP requests. Before booting from a network server, verify that a server is available by using the ping command.

Use the service config command to enable the loading of the specified configuration file at reboot time. Without this command, the router ignores the boot network command and uses the configuration information in NVRAM. If the configuration information in NVRAM is invalid or missing, the service config command is enabled automatically.

The network server will attempt to load two configuration files from remote hosts. The first is the network configuration file containing commands that apply to all network servers on a network. Use the boot network command to identify the network configuration file. The second is the host configuration file containing commands that apply to one network server in particular. Use the boot host command to identify the host configuration file.

Usually, the service config command is used in conjunction with the boot host or boot network command. You must enter the service config command to enable the router to automatically configure the system from the file specified by the boot host or boot network command. With IOS software versions 12.3(2)T , 12.3(1)B, and later, you no longer have to specify the service config command for the boot host or boot network command to be active. If you specify both the no service config command and the boot host command, the router attempts to find the specified host configuration file. The service config command can also be used without the boot host or boot network command. If you do not specify host or network configuration filenames, the router uses the default configuration files. The default network configuration file is network-confg. The default host configuration file is host-confg, where host is the hostname of the router. If the Cisco IOS software cannot resolve its hostname, the default host configuration file is router-confg.

Loading a Configuration File Using rcp

The rcp software requires that a client send the remote username on each rcp request to the network server. If the server has a directory structure (such as UNIX systems), the rcp implementation searches for the configuration files starting in the directory associated with the remote username.

When you load a configuration file from a server using rcp, the Cisco IOS software sends the first valid username in the following list:

The username specified in the file-URL, if a username is specified.

The username set by the ip rcmd remote-username command, if the command is configured.

The router host name.

An account for the username must be defined on the destination server. If the network administrator of the destination server did not establish an account for the username, this command will not execute successfully.

Loading a Configuration File Using FTP

The FTP protocol requires a client to send a remote username and password on each FTP request to a server. The username and password must be associated with an account on the FTP server. If the server has a directory structure, the configuration file or image copied from the directory associated with the username on the server. Refer to the documentation for your FTP server for more details.

When you load a configuration file from a server using FTP, the Cisco IOS software sends the first valid username in the following list:

The username specified in the boot network command, if a username is specified.

The username set by the ip ftp username command, if the command is configured.

The router sends the first valid password in the following list:

The password specified in the boot network command, if a password is specified.

The password set by the ip ftp password command, if the command is configured.

The router forms a password username @routername .domain . The variable username is the username associated with the current session, routername is the configured host name, and domain is the domain of the router.

Examples

The following example changes the network configuration filename to bridge_9.1 and uses the default broadcast address:

The following example changes the network configuration filename to bridge_9.1, specifies that rcp is to be used as the transport mechanism, and gives 172.16.1.111 as the IP address of the server on which the network configuration file resides:

Related Commands

Specifies the remote location and filename of the host-specific configuration file to be used at the next system boot (startup).

Enables autoloading of configuration files from a remote host.

boot system

To specify the system image that the router loads at startup, use one of the following boot system command in global configuration mode. To remove the startup system image specification, use the no form of this command.

Loading System Image from a URL or a TFTP File

Booting from a System Image in Internal Flash

boot system flash [ flash-fs : ] [ partition-number : ] [filename]

no boot system flash [ flash-fs : ] [ partition-number : ] [filename]

Booting from a MOP Server

boot system mop filename [mac-address] [interface]

no boot system mop filename [mac-address] [interface]

Booting from ROM

boot system rom

no boot system rom

Booting a System Image from a Network, TFTP, or FTP Server

boot system < rcp | tftp | ftp >filename [ip-address]

no boot system < rcp | tftp | ftp >filename [ip-address]

Syntax Description

The URL of the system image to load at system startup.

The TFTP filename of the system image to load at system startup.

On all platforms except the Cisco 1600 series, Cisco 3600 series, and Cisco 7000 family routers, this keyword boots the router from internal flash memory. If you omit all arguments that follow this keyword, the system searches internal Flash for the first bootable image.

On the Cisco 1600 series, Cisco 3600 series, and Cisco 7000 family routers, this keyword boots the router from the flash system specified by the flash-fs : argument. On the Cisco 1600 series and Cisco 3600 series routers, if you omit all optional arguments, the router searches internal flash memory for the first bootable image. On the Cisco 7000 family routers, when you omit all arguments that follow this keyword, the system searches the Personal Computer Memory Card Industry Association (PCMCIA) slot 0 for the first bootable image.

(Optional) Flash file system containing the system image to load at startup. The colon is required. Valid file systems are as follows:

flash: —Internal flash memory on the Cisco 1600 series and Cisco 3600 series routers. For the Cisco 1600 series and Cisco 3600 series routers, this file system is the default if you do not specify a file system. This is the only valid file system for the Cisco 1600 series.

bootflash: —Internal flash memory in the Cisco 7000 family.

slot0: —First PCMCIA slot on the Cisco 3600 series and Cisco 7000 family routers . For the Cisco 7000 family routers , this file system is the default if you do not specify a file system.

slot1: —Flash memory card in the second PCMCIA slot on the Cisco 3600 series and Cisco 7000 family routers.

On the Cisco 2600 series routers, a file system should be specified. Otherwise, the router may attempt to load the Cisco IOS software twice with unexpected results.

(Optional) Number of the flash memory partition that contains the system image to boot, specified by the optional filename argument. If you do not specify a filename, the router loads the first valid file in the specified partition of flash memory. This argument is valid only on routers that can be partitioned.

(Optional when used with the boot system flash command) Name of the system image to load at startup. This argument is case sensitive. If you do not specify a value for the filename argument, the router loads the first valid file in the following:

The specified flash file system

The specified partition of flash memory

The default flash file system if you also omitted the flash-fs : argument

Boots the router from a system image stored on a DECNET Maintenance Operations Protocol (MOP) server. Do not use this keyword with the Cisco 3600 series or Cisco 7000 family routers .

(Optional) MAC address of the MOP server containing the specified system image file. If you do not include the MAC address argument, the router sends a broadcast message to all MOP boot servers. The first MOP server to indicate that it has the specified file is the server from which the router gets the boot image.

(Optional) Interface the router uses to send out MOP requests to the MOP server. The interface options are async , dialer , ethernet , serial , and tunnel . If you do not specify the interface argument, the router sends a request out on all interfaces that have MOP enabled. The interface that receives the first response is the interface the router uses to load the software.

Boots the router from ROM. Do not use this keyword with the Cisco 3600 series or the Cisco 7000 family routers .

Boots the router from a system image stored on a network server using rcp.

Boots the router from a system image stored on a TFTP server.

Boots the router from a system image stored on an FTP server.

(Optional) IP address of the server containing the system image file. If omitted, this value defaults to the IP broadcast address of 255.255.255.255.

Command Default

If you configure the router to boot from a network server but do not specify a system image file with the boot system command, the router uses the configuration register settings to determine the default system image filename. The router forms the default boot filename by starting with the word cisco and then appending the octal equivalent of the boot field number in the configuration register, followed by a hyphen (-) and the processor type name (cisconn-cpu). Refer to the appropriate hardware installation guide for details on the configuration register and default filename. See also the config-register or confreg command.