Can i issue command "copy startup-config running-config" when i wanted to fallback to original?

[getaway51]

I enter some wrong commands in cisco switch. But i havent saved (wr mem) Therefore I wanted to fallback to original state. Can i issue this command? Do i need to "wr mem" after this command? 

ahgd6763#copy startup-config running-config 

[omz · Accepted solution]

Router# configure replace nvram:startup-config

Refer to this post - 

http://packetlife.net/blog/2010/may/17/use-configure-replace-instead-of-copy-start-run/

[Edwin Portillo]

Hi my friend,

running-config (system): command displays the active configuration in memory (including saved configuration changes) on the adaptive security appliance.

startup-config (Non-volatile random access memory): Shows the configuration saved in the NVRAM.

The write memory command has been replaced by the copy system:running-config nvram: startup-config command.

Puedes revisar el siguiente material sera de ayuda para ti: https://www.cisco.com/c/en/us/td/docs/ios/12_2/configfun/command/reference/ffun_r/frf006.html#wpxref54869

[Martin L]

on newer models wr m does not work but wr still does

[Vince Williams]

You can also just reload the device and it will load the config from memory; make sure you don't save the running config if it asks you.

[Joseph W. Doherty]

Yes you can issue the command but a copy startup to running does (by default) a merge not a replace. I.e. it likely won't undo the commands you've entered.

This is explained in the reference OMZ provided, along with the configure replace command. The only issue I had using the configure replace command, sometimes it doesn't work correctly. If it does work, you don't need to save the running config as it should now be the same as the startup config.

An alternative (as described by Vince), assuming as you've described you haven't saved the running config, is to reload the device, this will use the startup config.

[samuelnwadike]

If you haven't saved the new configuration, no need to complicate things always keep it simple you can unplug,  you can reset. I would advise the first. however copy start run would work but but possibly merge any new configurations you make with your start up so if you make mistakes again you might be stuck. 

copy start run is best when recovery forgotten "enable secret" from rom monitor (rommon).