Hi again,
thank you guys, really appreciate the speed and quality of your answers!
As it happens the device connected is a Ubiquity Bullet. (Titanium M2HP)
You think it would be easier to block the port there?
Any hints how to do this the easiest way?
Please assume - if you don't do it already - that I am not a networking expert. 
To give you a short description of the scenario might help:
We have several self-driving vehicles, each of these connected to one common WLAN with a Bullet.
Within each vehicle we have a local LAN, switched by an EdgeRouter.
The issue I try to solve is the following:
Each vehicle contains a GPS unit that broadcasts (UDP) the GPS data at 100/sec.
This data is used locally within the vehicle only and I do not want to sacrifice WLAN bandwith for this.
So I want to block this traffic from going over the WLAN.
I understand that I might solve this by using some kind of routing functionality, however there are some constraints:
- I need fixed IP addresses for all devices
- The devices shall be interchangeable between vehicles without altering the IP address
- There are UDP broadcasts that shall be forwarded to all devices
Again thank you in advance for any hints and tips
regards
Luigi