It works! MaxInterfaces=0 deactivates the UDP backend [CmpBlkDrvUdp] MaxInterfaces=0 Thank you!
Because it starts listening on all interfaces, which is against security considerations.
Is it possible to completely deactivate CmpBlkDrvUdp? I managed to practically deactivate it by setting MaxRouters=1 in [CmpRouter], but in the log there are warnings: !!!! No router instance found to assign network interface <interface>ether 6</interface> [CmpRouter] MaxRouters=1 0.MainNet=BlkDrvTcp [CmpBlkDrvTcp] Name=BlkDrvTcp Codesys Runtime 4.10.0.0 Is there a setting in [CmpBlkDrvUdp] which would deactivate it?