[Day 6] 3. Backup and Restore

Backup Procedures:

To back up the Running, Startup, or IOS configurations, use TFTP (Trivial File Transfer Protocol), which operates over UDP.

The basic command syntax is:

A#copy <source> <destination>

Examples:

• Copy

  **A#copy run tftp**:

  Back up the running configuration to TFTP.
• Copy

  A#copy start tftp

  : Back up the startup configuration to TFTP.
• Copy

  **A#copy flash tftp**

  : Back up the IOS image from flash to TFTP.

During the process, you'll be prompted for:

1. The IP address of the TFTP server.
2. The source file name (automatically taken unless using the
   Copy

   flash

   command, where you must specify the file).

Why Backup Router Configurations?

1. Disaster Recovery: Quickly restore configurations after failures.
2. Minimizing Downtime: Fast restoration reduces network downtime.
3. Testing Safety: Easily roll back configurations if changes cause issues.
4. Consistency: Ensure uniform configurations across multiple devices.
5. Compliance: Maintain configuration records for audits and security.
6. Hardware Upgrades: Transfer configurations to new devices.
7. Troubleshooting: Compare previous configurations to resolve issues.

Backup Best Practices:

• Always backup configurations before performing any major changes.
• Keep multiple backup copies, stored securely.

Backing Up IOS:

Before upgrading to a new IOS version, ensure you back up the current one. This provides a fallback in case the upgrade fails.

Use the following commands before backing up the IOS:

• Copy

  A#show flash

  : To view the contents and available space on the flash memory.
• Copy

  A#show version

  : To check the current IOS version and other system information.

Restore Procedures:

To restore configurations or IOS from a TFTP server, use the following commands:

• Copy

  **A#copy tftp flash**:

  Restore an IOS image from TFTP to flash.
• Copy

  **A#copy tftp run**:

  Restore the running configuration from TFTP.
• Copy

  **A#copy tftp start**:

  Restore the startup configuration from TFTP.

When prompted, enter the following information:

• IP Address?: Example: 172.16.10.10 (the IP address of the TFTP server).
• Source File Name?: Example: 1700-config (the name of the backup file).
• Destination File Name?: Specify the file name or accept the default.

If restoring to flash, you'll be asked:
Erase flash? (yes/no): Enter yes to free up space for the new IOS image.

Key Considerations:

• Insufficient Memory: If there's insufficient memory during the process, the command will fail, returning you to the prompt. If you've erased the flash and encounter an error, do not restart the router until the issue is resolved, or you risk losing the IOS permanently. However, if the IOS was backed up beforehand, it can be restored.

• Flash Memory Requirements: Always check the flash memory capacity before upgrading the IOS. If there isn't enough space, upgrade the flash memory before proceeding.