TFTP Server Backup or Copy-Paste Configuration ?

[Anup Sasikumar]

Hi ,

I normally take bacup of all network devices in the infrastructure - ASA /Switches , using a TFTP Server? But lets say , If I copy paste all the configuration contents to a text file and remove the txt extension , would it be the same ? Would such a file when restored to the device work as desired ?

Please help.

Regards,

Anup Sasikumar

[Peter Paluch · Accepted solution]

Hello Anup,

I assume that you are talking about creating a backup of the running configuration that could in future be used as the startup-config file.

In theory, it should work. You would need to be very careful, though, about not mixing the show running-config with any other text that could appear on the screen, such as logging messages, the --More-- prompts etc. Also, by default, the text files produced by Cisco IOS use Unix-type EOL (the #LF character) instead of DOS-type EOL (#CR#LF). If you capture and store the running-config output under Windows, it will most probably be stored using DOS-type EOLs. You will need to verify if such file will be correctly processed as startup-config during device bootup.

Best regards,

Peter

[Anup Sasikumar]

Thank you for your response Peter.

That was indeed very helpful .

I was going through the two files - The TFTP backup file and the renamed .txt file

( I used  telnet [ip] -f [path][filename.txt] command to get the telnet output to a text file , so I could not see any ----More----- prompts. But I think if I had done a mere copy paste I would have got that as well on the file. I have also removed all the hostname like ASA5505# from the file. )

1. The only difference I see on the TFTP file is an extra line on top which says

    " Written by enable_15 at 20:08:44.812 UTC Fri Oct 12 2012"

I could not find it in the #sh run output file . Would it be a problem ?

2. I had enabled service password encryption. So all the passwords were showing as encrypted meaningless ones which is same in both the files.   Would I be getting back the same when I restore ?

3. Just out of curiosity , could you please help me with the significance of " ! " that seen in configurations ?

Many Thanks ,

Anup

[Peter Paluch]

Hello Anup,

You are welcome.

( I used telnet [ip] -f [path][filename.txt] command to get  the telnet output to a text file , so I could not see any ----More-----  prompts. But I think if I had done a mere copy paste I would have got  that as well on the file. I have also removed all the hostname like  ASA5505# from the file. )

I see. That seems to be a Windows-based telnet, am I correct? Regarding the ---More--- prompts, you can also use the terminal length 0 command that tells the router/switch to stop paginating the output (the terminal has infinite length).

1. The only difference I see on the TFTP file is an extra line on top which says 
    " Written by enable_15 at 20:08:44.812 UTC Fri Oct 12 2012" 
I could not find it in the #sh run output file . Would it be a problem ?

If the line starts with the ! exclamation mark (I do not see it here), this line is irrelevant. Every line starting with ! is considered a remark and is completely ignored.

2. I had enabled service password encryption. So all the passwords were  showing as encrypted meaningless ones which is same in both the files.    Would I be getting back the same when I restore ? 

Yes, the passwords will be correctly stored and imported. They will remain encrypted all the time, however.

3. Just out of curiosity , could you please help me with the significance of "!" that seen in configurations ? 

The exclamation mark is a symbol that tells the router/switch/ASA to ignore the subsequent text till the end of the line. These ! symbols are used to put textual explanations or comments into the configuration files. They also appear in the running-config to somewhat improve its readability (the running-config is generated by a process asking all IOS subsystems to produce their current configuration in text form, resulting into the complete running-config. Many of these subsystems separate their output using the ! marks).

Best regards,

Peter

[Anup Sasikumar]

You are awesome, Peter !

It was very expalinatory and it sure helped me understand more.

We have an secondary ASA5505 which is currently not being used in the infrastructure. I will check if the renamed text file works and will let you know !

Many Thanks,

Anup

[Peter Paluch]

Hi Anup,

Thank you very much And I am looking forward to knowing if the ASA liked the Windows-saved configuration file.

Take care!

Best regards,

Peter

[Joseph W. Doherty]

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One other difference you might notice, on many Cisco devices, when you save a config file via the copy command (e.g TFTP, FTP, RCP), the text may not have each line terminated with CRLF, as it likely will if you copy/paste.  If you open such a file with Windows notepad, text will appear run together.  Windows Wordpad will present file correctly (it can also easily save it with CRLF).  (Note:either format [i.e. with or without CRLF] can be [e.g. TFTP] copied onto the Cisco device.)