Information ( Custom Interface Type )

[GillesZor]

Hi everyone,

I'm currently using NetBox v4.6.5 along with the Branching plugin.

I needed custom interface types (like specific connector/cable types), so I modified InterfaceTypeChoices directly in choices.py. However, as per the NetBox documentation, FIELD_CHOICES in configuration.py does not support extending dcim.Interface.type natively.

Because of this, when attempting to merge a branch containing interfaces with these custom types, the merge fails with a validation error:
{'type': ["Value 'rj45' is not a valid choice."]}

It seems the branching merge validation checks against NetBox's stock choices/validators rather than picking up custom values injected via local code modifications.

Has anyone encountered this issue before? If so, how did you resolve or work around it?
If not, how do you handle custom interface types or connector tracking when working with the Branching plugin? (e.g., using Custom Fields instead?)

Thanks in advance for your insights!

[Kxrma47]

dcim.Interface.type is not an extensible FIELD_CHOICES field, so patching choices.py leaves other workers/plugins using NetBox's stock validator—which explains the branch merge failure. The supported fields are explicitly listed in the NetBox configuration docs, and interface type is not among them.

The stable workaround is a selection custom field such as connector_type on dcim.interface (plus a custom validator if it must be mandatory), while keeping the nearest stock interface type. Otherwise this needs a first-class NetBox core change; a local enum patch will remain fragile across upgrades and branching validation.