Is Cisco Cmd Wr As Same As Copy Running-config Startup-config

Is Cisco wr the Same as copy running-config startup-config? A Deep Dive into Cisco Configuration Saving

This article explores the crucial difference between the Cisco IOS commands wr (short for write) and copy running-config startup-config, both used to save network configurations. While they achieve a similar outcome – persisting your network settings – understanding their nuances is vital for effective network management. This will cover the specifics of each command and explain when you might choose one over the other.

What is write (or wr)?

The write command, often shortened to wr, is a quick and convenient way to save your running configuration to the startup configuration file. This means any changes you've made to the network's active configuration (the running-config) will be preserved even after a router or switch reboots. It’s a shorthand for the more explicit copy running-config startup-config command. Think of it as a shortcut for saving your work.

What is copy running-config startup-config?

This command explicitly copies the contents of the running configuration file to the startup configuration file. It's the more verbose but equally effective way to achieve the same result as wr. It clearly indicates the action being performed – copying data from one file to another. This command offers more control and transparency in the configuration saving process.

Are they functionally identical? Almost.

In most practical scenarios, wr and copy running-config startup-config are functionally equivalent. They both accomplish the same task: saving the currently active configuration to the startup configuration, ensuring that those settings are loaded the next time the device boots up. This is critical for maintaining consistent network settings and preventing configuration loss.

Key Differences and Considerations:

While functionally similar, subtle differences exist:

• Verbosity and Clarity: copy running-config startup-config is more explicit and easier to understand, especially for those new to Cisco IOS. wr is concise but potentially less clear.

• Error Handling: While both commands generally provide similar feedback on success or failure, the more explicit command might offer slightly more detailed error messages in some circumstances. This can be beneficial during troubleshooting.

• Specific IOS Versions: While extremely rare, very old or highly specialized Cisco IOS versions might have slightly different behaviors with these commands. However, this is unlikely to be a concern in modern networking environments.

• Potential for Misunderstanding: The brevity of wr could lead to confusion, particularly in a team environment. The longer command provides better context and reduces the likelihood of misinterpretations.

Best Practices:

• Consistency: Choose one method (either wr or copy running-config startup-config) and stick to it consistently across your network devices. This improves clarity and reduces the risk of errors.

• Explicitness: For better readability and clarity, especially in scripts or automated processes, copy running-config startup-config is preferred.

• Verification: After using either command, always verify the configuration has been saved correctly by checking the startup-config file using the show startup-config command. This provides an extra layer of security and ensures your settings are persistent.

Conclusion:

Both wr and copy running-config startup-config save Cisco device configurations. While functionally almost identical in most situations, choosing copy running-config startup-config provides better clarity, readability, and potentially more detailed error handling. Consistency in your chosen method is key to effective network management. Always verify the save operation to ensure your network configuration is secure and persistent.