You can duplicate files or data in the router from one location to another using the copy command. This functionality helps to create a copy of a file, folder, or data set and place it in a specific destination. You can use the copy functionality to back up files, move data between directories, create duplicates of the files for editing or distribution without modifying the original content. It also allows you to retain the original data while making a duplicate that you can further manipulate independently.

Starting with Cisco IOS XR Release 7.9.1, we’ve enhanced the functionality of the copy command to support secure file transfer from the router. Secure file transfer protects data during transit using the SFTP (Secure File Transfer Protocol) and SCP (Secure Copy Protocol) when sharing files within or across networks. The SFTP and SCP functionalities in the copy feature use the SSH protocol implementation in the router to secure transfer the files to a remote server.

You can use the following options in the copy command for secure file transfer:

• sftp: You can transfer the files to a remote location using the SFTP file transfer protocol. SFTP is a secure file transfer protocol for transferring large files.

• scp: You can transfer the files to a remote location using the SCP file transfer protocol. SCP is a secure copy protocol to transfer files between servers.

Prerequisites:

Enable the SSH Server in the router as follows:

Router# config
Router(config)# ssh server v2
Router(config)# ssh server vrf default
Router(config)# ssh server netconf vrf default
Router(config)# commit

Configuration Example for Secure File Transfer Protocol

You can copy the running configuration file from the router to a remote server using SFTP:

Configuration in the Router

Router# copy running-config sftp://root:testpassword@192.0.2.1//var/opt/run_conf_sftp.txt 

Destination file name (control-c to cancel): [/var/opt/run_conf_sftp.txt]?

.
215 lines built in 1 second
[OK]Connecting to 192.0.2.1...22
Password: 
sftp> put /tmp/tmpsymlink/nvgen-34606-_proc_34606_fd_75 /var/opt/run_conf_sftp.txt


/tmp/tmpsymlink/nvgen-34606-_proc_34606_fd_75

  Transferred 3271 Bytes
  3271 bytes copied in 0 sec (3271000)bytes/sec
sftp> exit

Verification in the SFTP Server

[root@sftp_server ~]# ls -ltr /var/opt/run_conf_sftp.txt
-rw-r--r-- 1 root root 3271 Mar 21 18:07 /var/opt/run_conf_sftp.txt

Configuration Example for Secure Copy Protocol

You can copy the running configuration file from the router to a remote server using SCP:

Configuration in the Router

Router# copy running-config scp://root:testpassword@192.0.4.2//var/opt/run_conf_scp.txt

Destination file name (control-c to cancel): [/var/opt/run_conf_scp.txt]?

.
215 lines built in 1 second
[OK]Connecting to 192.0.4.2...22
Password: 

  Transferred 3271 Bytes
  3271 bytes copied in 0 sec (0)bytes/sec

Verification in the SCP Server

[root@scp_server ~]# ls -ltr /var/opt/run_conf_scp.txt
-rw-r--r-- 1 root root 3271 Mar 21 18:07 /var/opt/run_conf_scp.txt

You can configure the router to automatically take the backup of the running configuration by using configuration commit auto-save command. This auto-save feature saves the configuration to the specified location on the router after every commit is made. These auto-save files are stored in the form of Linux files.

From Cisco IOS XR Software Release 7.10.1, you don't need to remember and enter the password as you can use public key-based authentication while doing the following:

• Automatically saving your running configuration

• Copying the configuration from a source (such as a network server) to a destination (such as a flash disk)

Password is automatically verified when you have enabled SSH connection using public key-based authentication. Using public key-based authentication avoids several problems such as password disclosure and password leakage.

Public key is mathematically related to private key. The private key is secret, whereas the public key is available on the servers. You can copy the public key to the SSH server from the SSH client. Then, when you try to secure the running configuration, the SSH server tries to authenticate by generating a challenge using the public key. Only the private key can answer this challenge. As the keys are related, log-in is successful.

Prerequisites for Auto-Save and Copy Router Configuration Using Public Key Authentication

Ensure you have enabled public key-based authentication of SSH clients, using the following steps:

• Generate RSA key pair on the router configured as the SSH client. Use the cyrpto key generate authentication-ssh rsa command to generate the RSA key pair.

• Use the show crypto key mypubkey authentication-ssh rsa command to view the details of the RSA key. The key value starts with ssh-rsa in this output.

• Copy the RSA public key from the SSH client to the SSH server.

For more detailed information on how to enable SSH connection using public-key based authentication, see Public Key Based Authentication of SSH Clients in System Security Configuration Guide for Cisco NCS 5500 Series Routers.

The Cisco IOS XR Routers use a two-stage configuration model. The first stage is target configuration, where you build the configurations using the necessary commands in the command line interface. The second stage is the commit, where the configuration made in the target stage is added to the router configuration using the commit command. After each commit, the router generates a file for the newly configured changes and adds it to its running configuration, making it an integral part of the running configuration.

Note	This target configuration doesn’t impact the router's running configuration.

The Cisco IOS XR routers perform rebase and ASCII backup operations to maintain the real time configuration in the backup copy. The rebase and ASCII backup operations block you from committing configurations to the router.

In rebase, the router automatically saves your changes to the backup binary configuration file after 20 commits, or 2 MB of configuration data. The router blocks the commit while saving the configuration to the backup file. The router takes a few seconds to complete the rebase operation, during which, if you terminate the CLI session, the router loses the target configurations in the blocked commit.

In ASCII backup, the router automatically saves a copy of its running configuration in the ASCII format. This backup process takes place if there has been a commit to the router configuration and when the ASCII backup timer completes a 55-minute window after the previous backup event. However, if there was no commit when the ASCII backup timer completes 55 minutes, the counter is reset without any backup. During the ASCII backup, the router blocks the configuration commits.

Starting with , we have made the following enhancements:

• You can use the cfs check command to increase the rebase limits in the router from 20 to 40 commits and the configuration data from 2 MB to 4 MB. When configuring the router, you can check the current commit count and configuration data size using the show cfgmgr commitdb command. If the commit count is 20 or higher, or the configuration data size is 2 MB or above, the router initiates a rebase within 10 seconds. By using the cfs check command to increase the commit count to 40 and the configuration data to 4 MB, you can commit without delay.

• You can use the clear configuration ascii inconsistency command to perform an ASCII backup and reset the ASCII backup timer to zero. Once the backup is complete, the router will automatically initiate the next periodic ASCII backup operation only after 55 minutes from the time the clear configuration ascii inconsistency command is executed.