Working with Configuration Files

This chapter contains the following sections:

About Configuration Files

Configuration files contain the Cisco NX-OS software commands used to configure the features on a Cisco NX-OS device. Commands are parsed (translated and executed) by the Cisco NX-OS software when the system is booted (from the startup-config file) or when you enter commands at the CLI in a configuration mode.

To change the startup configuration file, you can either save the running-configuration file to the startup configuration using the copy running-config startup-config command or copy a configuration file from a file server to the startup configuration.

Types of Configuration Files

The Cisco NX-OS software has two types of configuration files, running configuration and startup configuration. The device uses the startup configuration (startup-config) during device startup to configure the software features. The running configuration (running-config) contains the current changes that you make to the startup-configuration file. The two configuration files can be different. You might want to change the device configuration for a short time period rather than permanently. In this case, you would change the running configuration by using commands in global configuration mode but not save the changes to the startup configuration.

To change the running configuration, use the configure terminal command to enter global configuration mode. As you use the Cisco NX-OS configuration modes, commands generally are executed immediately and are saved to the running configuration file either immediately after you enter them or when you exit a configuration mode.

To change the startup-configuration file, you can either save the running configuration file to the startup configuration or download a configuration file from a file server to the startup configuration.

Guidelines and Limitations for Configuration Files

Configuration file guidelines and limitations are as follows:

  • Beginning with NX-OS 7.0(3)I7(4), the reload timer command is supported to enable a reboot after a delay of 5 -60 seconds.

Managing Configuration Files

This section describes how to manage configuration files.

Saving the Running Configuration to the Startup Configuration

You can save the running configuration to the startup configuration to save your changes for the next time you that reload the device.

SUMMARY STEPS

  1. (Optional) show running-config
  2. copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

(Optional) show running-config

Example:

switch# show running-config
 (Optional)

Displays the running configuration.

Step 2

copy running-config startup-config

Example:

switch# copy running-config startup-config

Copies the running configuration to the startup configuration.

Copying a Configuration File to a Remote Server

You can copy a configuration file stored in the internal memory to a remote server as a backup or to use for configuring other Cisco NX-OS devices.

SUMMARY STEPS

  1. copy running-config scheme://server/[url /]filename
  2. copy startup-config scheme://server/[url /]filename

DETAILED STEPS

  Command or Action Purpose

Step 1

copy running-config scheme://server/[url /]filename

Example:

switch# copy running-config 
tftp://10.10.1.1/sw1-run-config.bak

Copies the running-configuration file to a remote server.

For the scheme argument, you can enter tftp: , ftp: , scp: , or sftp: . The server argument is the address or name of the remote server, and the url argument is the path to the source file on the remote server.

The server, url, and filename arguments are case sensitive.

Step 2

copy startup-config scheme://server/[url /]filename

Example:

switch# copy startup-config 
tftp://10.10.1.1/sw1-start-config.bak

Copies the startup-configuration file to a remote server.

For the scheme argument, you can enter tftp: , ftp: , scp: , or sftp: . The server argument is the address or name of the remote server, and the url argument is the path to the source file on the remote server.

The server, url, and filename arguments are case sensitive.

Example

This example shows how to copy the configuration file to a remote server: 


switch# copy running-config 
tftp://10.10.1.1/sw1-run-config.bak
switch# copy startup-config 
tftp://10.10.1.1/sw1-start-config.bak

Downloading the Running Configuration From a Remote Server

You can configure your Cisco NX-OS device by using configuration files that you created on another Cisco NX-OS device and uploaded to a remote server. You then download the file from the remote server to your device using TFTP, FTP, Secure Copy (SCP), or Secure Shell FTP (SFTP) to the running configuration.

Before you begin

Ensure that the configuration file that you want to download is in the correct directory on the remote server.

Ensure that the permissions on the file are set correctly. Permissions on the file should be set to world-read.

Ensure that your device has a route to the remote server. Your device and the remote server must be in the same subnetwork if you do not have a router or a default gateway to route traffic between subnets.

Check connectivity to the remote server using the ping or ping6 command.

SUMMARY STEPS

  1. copy scheme://server/[url/]filename running-config
  2. (Optional) show running-config
  3. (Optional) copy running-config startup-config
  4. (Optional) show startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

copy scheme://server/[url/]filename running-config

Example:

switch# copy tftp://10.10.1.1/my-config 
running-config

Downloads the running-configuration file from a remote server.

For the scheme argument, you can enter tftp: , ftp: , scp: , or sftp: . The server argument is the address or name of the remote server, and the url argument is the path to the source file on the remote server.

The server, url, and filename arguments are case sensitive.

Step 2

(Optional) show running-config

Example:

switch# show running-config
 (Optional)

Displays the running configuration.

Step 3

(Optional) copy running-config startup-config

Example:

switch# copy running-config startup-config
 (Optional)

Copies the running configuration to the startup configuration.

Step 4

(Optional) show startup-config

Example:

switch# show startup-config
 (Optional)

Displays the startup configuration.

Downloading the Startup Configuration From a Remote Server

You can configure your Cisco NX-OS device by using configuration files that you created on another Cisco NX-OS device and uploaded to a remote server. You then download the file from the remote server to your device using TFTP, FTP, Secure Copy (SCP), or Secure Shell FTP (SFTP) to the startup configuration.


Caution

This procedure disrupts all traffic on the Cisco NX-OS device.

Before you begin

Log in to a session on the console port.

Ensure that the configuration file that you want to download is in the correct directory on the remote server.

Ensure that the permissions on the file are set correctly. Permissions on the file should be set to world-read.

Ensure that your device has a route to the remote server. Your device and the remote server must be in the same subnetwork if you do not have a router or a default gateway to route traffic between subnets.

Check connectivity to the remote server using the ping or ping6 command.

SUMMARY STEPS

  1. write erase
  2. reload
  3. copy scheme://server/[url /]filename running-config
  4. copy running-config startup-config
  5. (Optional) show startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

write erase

Example:

switch# write erase

Erases the startup configuration file.

Step 2

reload

Example:

switch# reload
This command will reboot the system. (y/n)?  [n] y
...
Enter the password for "admin": <password>
Confirm the password for "admin": <password>
...
Would you like to enter the basic configuration 
dialog (yes/no): n
switch#

Reloads the Cisco NX-OS device.

Note

 

Do not use the setup utility to configure the device.

Step 3

copy scheme://server/[url /]filename running-config

Example:

switch# copy tftp://10.10.1.1/my-config 
running-config

Downloads the running configuration file from a remote server.

For the scheme argument, you can enter tftp: , ftp: , scp: , or sftp: . The server argument is the address or name of the remote server, and the url argument is the path to the source file on the remote server.

The server, url, and filename arguments are case sensitive.

Step 4

copy running-config startup-config

Example:

switch# copy running-config 
startup-config

Saves the running configuration file to the startup configuration file.

Step 5

(Optional) show startup-config

Example:

switch# show startup-config
 (Optional)

Displays the running configuration.

Copying Configuration Files to an External Flash Memory Device

You can copy configuration files to an external flash memory device as a backup for later use.

Before you begin

Insert the external Flash memory device into the active supervisor module.

SUMMARY STEPS

  1. (Optional) dir {usb1: | usb2:}[directory/]
  2. copy running-config {usb1: | usb2:}[directory/]filename
  3. copy startup-config {usb1: | usb2:}[directory/]filename

DETAILED STEPS

  Command or Action Purpose

Step 1

(Optional) dir {usb1: | usb2:}[directory/]

Example:

switch# dir usb1:
 (Optional)

Displays the files on the external flash memory device.

Step 2

copy running-config {usb1: | usb2:}[directory/]filename

Example:

switch# copy running-config usb1:dsn-running-config.cfg

Copies the running configuration to an external flash memory device. The filename argument is case sensitive.

Step 3

copy startup-config {usb1: | usb2:}[directory/]filename

Example:

switch# copy startup-config usb1:dsn-startup-config.cfg

Copies the startup configuration to an external flash memory device. The filename argument is case sensitive.

Copying the Running Configuration from an External Flash Memory Device

You can configure your device by copying configuration files created on another Cisco NX-OS device and saved to an external flash memory device.

Before you begin

Insert the external flash memory device into the active supervisor module.

SUMMARY STEPS

  1. (Optional) dir {usb1: | usb2:}[directory/]
  2. copy {usb1: | usb2:}[directory/]filename running-config
  3. (Optional) show running-config
  4. (Optional) copy running-config startup-config
  5. (Optional) show startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

(Optional) dir {usb1: | usb2:}[directory/]

Example:

switch# dir usb1:
 (Optional)

Displays the files on the external flash memory device.

Step 2

copy {usb1: | usb2:}[directory/]filename running-config

Example:

switch# copy usb1:dsn-config.cfg running-config

Copies the running configuration from an external flash memory device. The filename argument is case sensitive.

Step 3

(Optional) show running-config

Example:

switch# show running-config
 (Optional)

Displays the running configuration.

Step 4

(Optional) copy running-config startup-config

Example:

switch# copy running-config startup-config
 (Optional)

Copies the running configuration to the startup configuration.

Step 5

(Optional) show startup-config

Example:

switch# show startup-config
 (Optional)

Displays the startup configuration.

Copying the Startup Configuration From an External Flash Memory Device

You can recover the startup configuration on your device by downloading a new startup configuration file saved on an external flash memory device.

Before you begin

Insert the external flash memory device into the active supervisor module.

SUMMARY STEPS

  1. (Optional) dir {usb1: | usb2:}[directory/]
  2. copy {usb1: | usb2:}[directory /]filename startup-config
  3. (Optional) show startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

(Optional) dir {usb1: | usb2:}[directory/]

Example:

switch# dir usb1:
 (Optional)

Displays the files on the external flash memory device.

Step 2

copy {usb1: | usb2:}[directory /]filename startup-config

Example:

switch# copy usb1:dsn-config.cfg startup-config

Copies the startup configuration from an external flash memory device. The filename argument is case sensitive.

Step 3

(Optional) show startup-config

Example:

switch# show startup-config
 (Optional)

Displays the startup configuration.

Copying Configuration Files to an Internal File System

You can copy configuration files to the internal memory as a backup for later use.

SUMMARY STEPS

  1. copy running-config [filesystem:][directory/] | [directory/]filename
  2. copy startup-config [filesystem:][directory/] | [directory/]filename

DETAILED STEPS

  Command or Action Purpose

Step 1

copy running-config [filesystem:][directory/] | [directory/]filename

Example:

switch# copy running-config bootflash:sw1-run-config.bak

Copies the running-configuration file to internal memory.

The filesystem , directory , and filename arguments are case sensitive.

Step 2

copy startup-config [filesystem:][directory/] | [directory/]filename

Example:

switch# copy startup-config bootflash:sw1-start-config.bak

Copies the startup-configuration file to internal memory.

The filesystem , directory , and filename arguments are case sensitive.

Rolling Back to a Previous Configuration

Problems, such as memory corruption, can occur that make it necessary for you to recover your configuration from a backed up version.


Note

Each time that you enter a copy running-config startup-config command, a binary file is created and the ASCII file is updated. A valid binary configuration file reduces the overall boot time significantly. A binary file cannot be uploaded, but its contents can be used to overwrite the existing startup configuration. The write erase command clears the binary file.

SUMMARY STEPS

  1. write erase
  2. reload
  3. copy configuration-file running-configuration
  4. copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

write erase

Example:

switch# write erase

Clears the current configuration of the switch.

Step 2

reload

Example:

switch# reload

Restarts the device. You will be prompted to provide an nx-os image file for the device to boot and run.

Step 3

copy configuration-file running-configuration

Example:

switch# copy bootflash:start-config.bak running-configuration

Copies a previously saved configuration file to the running configuration.

Note

 

The configuration-file filename argument is case sensitive.

Step 4

copy running-config startup-config

Example:

switch# copy running-config startup-config

Copies the running configuration to the start-up configuration.

Removing the Configuration for a Missing Module

When you remove an I/O module from the chassis, you can also remove the configuration for that module from the running configuration.


Note

You can only remove the configuration for an empty slot in the chassis.

Before you begin

Remove the I/O module from the chassis.

SUMMARY STEPS

  1. (Optional) show hardware
  2. purge module slot running-config
  3. (Optional) copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

(Optional) show hardware

Example:

switch# show hardware
 (Optional)

Displays the installed hardware for the device.

Step 2

purge module slot running-config

Example:

switch# purge module 3 running-config

Removes the configuration for a missing module from the running configuration.

Step 3

(Optional) copy running-config startup-config

Example:

switch# copy running-config startup-config
 (Optional)

Copies the running configuration to the startup configuration.

Erasing a Configuration

You can erase the configuration on your device to return to the configuration defaults. "Configuration" refers to the startup configuration as seen in 'show startup'. No other internal application or process states are cleared.

Erase configuration feature is supported on the Nexus 9200-X, Nexus 9300-EX, -FX, -FX2, -FX3, and Nexus 9500 series switches.

You can erase the following configuration files saved in the persistent memory on the device:

  • Startup

  • Boot

  • Debug

The write erase command erases the entire startup configuration, except for the following:

  • Boot variable definitions

  • The IPv4 and IPv6 configuration on the mgmt0 interface, including the following:

    • Address

    • Subnet mask

    • Default Gateway/Route in the management VRF

To remove the boot variable definitions and the IPv4/IPv6 configuration on the mgmt0 interface, use the write erase boot command. To remove all application persistency files such as patch rpms, third party rpms, application configuration in /etc directory other than configuration, use 'install reset'. This command was added as of the 7.0(3)I6(1) release.


Note

When there are multiple IPv6 default routes present in the management VRF, the default route that is displayed first in the show ipv6 static-route command for the management VRF just before using ‘copy r s’ gets restored after the write erase and reload.


Note
After you enter the write erase command, you must reload the ASCII configuration twice to apply the breakout configuration.

SUMMARY STEPS

  1. write erase [boot | debug]

DETAILED STEPS

Command or Action Purpose

write erase [boot | debug]

Example:


switch# write erase
Warning: This command will erase the startup-configuration.
Do you wish to proceed anyway? (y/n)  [n] y

Erases configurations in persistent memory. The default action erases the startup configuration.

The boot option erases the boot variable definitions and the IPv4 configuration on the mgmt0 interface.

The debug option erases the debugging configuration.

Note

 

When you configure multiple IPv6 addresses on mgmt0 interface, the IPv6 address that is displayed first before the usage of ‘copy r s’ in the show ipv6 interface <intf> command gets restored on write erase and reload.

Note

 

The running-configuration file is not affected by this command.

Clearing Inactive Configurations

You can clear inactive QoS and/or ACL configurations.

SUMMARY STEPS

  1. (Optional) show running-config type inactive-if-config
  2. clear inactive-config policy
  3. (Optional) show inactive-if-config log

DETAILED STEPS

  Command or Action Purpose

Step 1

(Optional) show running-config type inactive-if-config

Example:

# show running-config ipqos inactive-if-config
 (Optional)

Displays any inactive access control list (ACL) or quality of service (QoS) configurations.

The values for the type argument are aclmgr and ipqos .

  • aclmgr —Displays any inactive configurations for aclmgr.

  • ipqos —Displays any inactive configurations for qosmgr.

Step 2

clear inactive-config policy

Example:

# clear inactive-config qos 
clear qos inactive config
Inactive if config for QoS manager is saved at/bootflash/qos_inactive_if_config.cfg for vdc default
you can see the log file @ show inactive-if-config log

Clears inactive configurations.

The values for the policy argument are qos and acl .

The following describes the values:

  • qos —Clears inactive QoS configurations.

  • acl —Clears inactive ACL configurations.

  • acl qos —Clears inactive ACL configurations and inactive QoS configurations.

Step 3

(Optional) show inactive-if-config log

Example:

# show inactive-if-config log
 (Optional)

Displays the commands that were used to clear the inactive configurations.

Configuration Archive and Configuration Log

This section contains information on configuration archive and configuration log.

Information About Configuration Archive

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

The archive config command allows you to save configurations in the configuration archive using a standard location and filename prefix that is automatically appended with an incremental version number (and optional timestamp) as each consecutive file is saved. This functionality provides a means for consistent identification of saved configuration files. You can specify how many versions of the running configuration are kept in the archive. After the maximum number of files are 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 configuration archive.

The configuration archive, wherein the configuration files are stored and are available for use with the configure replace command, can be located on the following file systems: bootflash, FTP, and TFTP.


Note

The TFTP and FTP for this feature use VRF management.

Configuring the Characteristics of the Configuration Archive

Before using the archive config command, the configuration archive must be configured. Complete the following steps to configure the characteristics of the configuration archive:

SUMMARY STEPS

  1. configure terminal
  2. archive
  3. path url
  4. maximum number
  5. time-period minutes
  6. write-memory
  7. archive config
  8. (Optional) show archive log config all

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:


switch# configure terminal

Enters the global configuration mode.

Step 2

archive

Example:


switch(config)# archive

Enters the archive configuration mode.

Note

 

This command does not apply to Cisco Nexus 9300-EX, -FX, and -R Series switches.

Step 3

path url

Example:


switch(config-archive)# path bootflash:myconfig

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

  • Depending on your hardware platform, the name of your file system can be different than the one displayed in the example.

Note

 

If a directory is specified in the path instead of the file, the directory name must be followed by a forward slash as follows: path flash:/directory /. The forward slash is not necessary after a filename; it is necessary only when specifying a directory.

Step 4

maximum number

Example:

switch(config-archive)# maximum 14

(Optional) Sets the maximum number of archive files of the running configuration to be saved in the configuration archive.

  • The number is the maximum number of the archive files of the running configuration that can be saved in the configuration archive. The range is 1 to 14. The default is 10.

Note

 

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

Step 5

time-period minutes

Example:

switch(config-archive)# time-period 10

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

  • The minutes argument specifies how often, in minutes, to automatically save an archive file of the current running configuration in the configuration archive.

Note

 

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

Step 6

write-memory

Example:

switch(config-archive)# write-memory

Enables the command. It is disabled by default. Entering this command causes an archive to occur when the command copy r s is performed.

Step 7

archive config

Example:

switch(config-archive)# archive config

Saves the current running configuration file to the configuration archive.

Note

 

You must configure the path before using the archive config command.

Step 8

(Optional) show archive log config all

Example:

switch# show archive log config all
 (Optional)

Displays the configuration log entries for all the users.

Information About Configuration Log

The configuration change logging tracks the changes that are made to the running configuration by using the data in the accounting log. This configuration log tracks the changes that are initiated only through the CLI. Only complete commands that result in the invocation of action routines are logged. The following types of entries are not logged:

  • Commands that result in a syntax error message

  • Partial commands that invoke the device help system

The configuration log tracks the changes that are initiated only through the CLI. For each configuration command that is executed, the following information is logged:

  • A configuration change sequence number

  • The line from which the command was executed

  • The name of the user that executed the command

  • The command that was executed

You can display the information from the configuration log by using the show archive log config all command

For each configuration command that is executed, the following information is logged:

  • The command that was executed

  • The name of the user that executed the command

  • A configuration change sequence number

You can display the information from the configuration log by using the show archive log config command.

Displaying Configuration Log Entries

To display the configuration log entries, the configuration change logging provides the show archive log config all command.

SUMMARY STEPS

  1. switch# show archive log config all
  2. switch# show archive log config user username
  3. switch# show archive log config user username first-index start-number [last-index end-number ]

DETAILED STEPS

Step 1

switch# show archive log config all

Displays the configuration log entries for all users

Example:


switch# show archive log config all

INDEX   LINE                    USER          LOGGED COMMAND
1       console0                user01       | logging console 1 
2       console0                user01       | logging monitor 2
3       console0                user02       | system default switchport shutdown  
4       console0                user02       | interface mgmt0 
5       console0                user02       |  no shutdown

Step 2

switch# show archive log config user username

Displays the configuration log entries for the specified username.

Example:

The following example displays the configuration log entries for a specified username.

switch# show archive log config user user02

INDEX   LINE                    USER          LOGGED COMMAND
3       console0                user02       | system default switchport shutdown 
4       console0                user02       | interface mgmt0 
5       console0                user02       |  no shutdown

Step 3

switch# show archive log config user username first-index start-number [last-index end-number ]

Displays the configuration log entries by the index numbers. If you specify a number for the optional last-index, all the log entries with the index numbers in the range from the value entered for the start-number through the end-number for the specified user are displayed.

Example:

The following example displays the configuration log entry numbers 4 and 5 for a user with the username, user02. The range for the first-index and last-index is 1 to 2000000000. 

switch# show archive log config user user02  first-index 4 last-index 5
Last Log cleared/wrapped time is : Wed Oct 19 00:53:08 2016


INDEX   LINE                    USER          LOGGED COMMAND
4       console0                user02       | interface mgmt0 
5       console0                user02       |  no shutdown

Verifying the Device Configuration

To verify the configuration, use one of the following commands:

Command

Purpose

show running-config

Displays the running configuration.

show startup-config

Displays the startup configuration.

Note

 

If Layer 3 based feature configurations are disabled in the running-config, the show startup-config command does not display them. However, the configurations remain intact in the startup PSS, until the copy running startup command is performed.

show time-stamp running-config last-changed

Displays the timestamp when the running configuration was last changed.

This option masks the sensitive words in running configuration output with <removed> keyword.

Examples of Working with Configuration Files

This section includes examples of working with configuration files.

Copying Configuration Files

This example shows how to overwrite the contents of an existing configuration in NVRAM: 

switch# copy nvram:snapshot-config nvram:startup-config
Warning: this command is going to overwrite your current startup-config.
Do you wish to continue? {y/n} [y] y

Note

This command does not apply to Cisco Nexus 9300-EX Series switches.

This example shows how to copy a running configuration to the bootflash: file system: 

switch# copy system:running-config bootflash:my-config

Backing Up Configuration Files

This example shows how to back up the startup configuration to the bootflash: file system (ASCII file): 

switch# copy startup-config bootflash:my-config

This example shows how to back up the startup configuration to the TFTP server (ASCII file): 

switch# copy startup-config tftp://172.16.10.100/my-config

This example shows how to back up the running configuration to the bootflash: file system (ASCII file): 

switch# copy running-config bootflash:my-config

Rolling Back to a Previous Configuration

To roll back your configuration to a snapshot copy of a previously saved configuration, you need to perform the following steps:

  1. Clear the current running image with the write erase command.

  2. Restart the device with the reload command.

  3. Copy the previously saved configuration file to the running configuration with the copy configuration-file running-configuration command.

  4. Copy the running configuration to the start-up configuration with the copy running-config startup-config command.