Technical Tip: Cannot change interface IP address to default error 'Error: IP address x.x.x.x is configured as source-ip for syslog or other servers'

[mpeddalla]

Description	This article describes how to change the interface IP address to default 0.0.0.0/0.0.0.0.
Scope	FortiGate.
Solution	Seeing error 'Error: IP address x.x.x.x is configured as source-ip for syslog' when changing interface IP address: There will be requirements in the network sometimes to change switch ports which can support high-speed bandwidth on the interface would like to migrate the port address to a different port on the same device while changing the existing address on the interface would show the above error when changing IP address to different address or to 0.0.0.0/0.0.0.0.  Check which address the error refers to and unset the IP address of the interface address. For example in the below image on the interface, it is not possible to change the IP address even though there are no references. But in the error message, it is referring to syslogd settings where the interface IP address is being used.      2. Remove the dependencies references by checking error messages. In the below screenshot, the source IP address of the interface which was referenced under syslogd server according to the error in step 1 referring has been unset. It is possible to make note of changes or take backup configuration files before changes and add them back once if needed accordingly.      3. After checking all dependencies errors referring to, it is possible to change the interface IP address to 0.0.0.0/0.0.0.0 default address.   Once the address is changed, it is possible to use the same address on a different interface and update all existing firewall policies, static routes etc. If there is a FortiManager, it will be possible to push all changes from FortiManager once the interface address is updated on FortiManager. If there is no FortiManager, it will be necessary to manually change everything.