Network Management

Error when downloading configs from F5 devices in NCM

Failed to download F5 config backups: Syntax Error: An unexpected argument "tmsh" can be seen in the session trace, or if one would log in to the devices.

First published date

10/22/2018 4:00 PM

Last published date

1/6/2025 10:12 PM

Overview

When you download a configuration from an F5 device, NCM tries to send Traffic Management Shell (TMSH) commands. If the user assigned to the device does not have rights to issue the command from a Traffic Management Operating System (TMOS) level, the login validation may pass, but the download will fail.

The following error cam be seen in the session traces:

 

Syntax Error: An unexpected argument "tmsh"

 

Also, if you log in to the command line interface (CLI) on the device with the same credentials from an SSH or Telnet client (such as PuTTY or Secure CRT) and issue a TMSH command like 

tmsh show /system version


a similar error displays.

Product section

Network Configuration Manager

Resolution

Provide the F5 user an administrator role to switch the bash and issue the command.

  1. From the Web Console, go to settings > NCM settings > Device Templates and look for the the f5 BIG IP Device template.
  2. Turn the Use for Auto Detect to Off.
  3. Edit the Device Template(this will force a copy).
  4. Rename the copy then set the Use for auto-detect to Yes.

 

Modify the following command:

<Command Name="RESET" Value=""/>

 

Use the same line and add run /util bash:

<Command Name="RESET" Value="run /util bash" RegEx="#"/>

 

 

The RegEx=''#'' was added at the end of the command since the prompt will change from (TMOS)# to maybe (standby)~#. This will tell NCM to accept the # as the prompt regardless of what precedes it. 

 

Note:  According to F5 article K10272, remote users attempting to run this command that do not have advanced shell privileges see the following error:

Syntax Error: "bash" unexpected argument"