Technical Tip: Unable to change name or configuration of a managed FortiSwitch from FortiGate GUI or CLI due illegal characters in switch name

In FortiOS v7.6.4, if a FortiLink managed switch-name contains an illegal character, it is not possible to rename the switch or change settings on that switch. This is often due to illegal characters having been present before upgrading to FortiOS v7.6.4.

Example of the issue:

config switch-controller managed-switch

(managed-switch) # edit Test.06

The legal allowed characters are numbers (0-9), letters(a-z,A-z) and special characters - and _
node_check_object fail! for switch-id Test.06

value parse error before 'Test.06'
Command fail. Return code -651

FortiOS v7.6.5, v8.0.0 will allow an administrator to rename managed FortiSwitches that have illegal characters to a name without illegal characters. 

Workaround:

1. Backup configuration file from the problematic device.

2. Rename the switch using only allowed characters:

   • Numbers: 0–9.

   • Letters: a–z, A–Z.

   • Special characters: '-' and '_'.

3. Restore the modified backup file. The configuration should now apply successfully.