We have bought the Greenbone virtual Appliance DECA.
In the Greenbone documentation i read some things about namespaces, namespace separation etc. (management and scan only). But only the Appliances 400/450/600/650 and 5400/6500 are mentioned.
So am i right that the namespaces are only available for hardware appliances, not for virtual appliances?
The hardware appliances, separate Management and Scan-Interfaces via Namespaces and hardware features, that is not available via virtual appliances.
With the hardware, you can have a internal management port, and a external scan-interface with a different outgoing IP address, on the VM your Hypervisor can be configures for such a setup.