Short answer: at HiOS devices you can restrict access to read-only.
Detailed answer:
EtherNet/IP - like the other industrial protocols - use insecure communication. A secure communication is provided by SNMPv3, which offers authentication and even encryption for the data. SNMPv3 is standardized for years and available in nearly all industrial switches. For network management tools like Hirschmann Industrial HiVision are available to centrally manage all SNMP devices, e.g. configure multiple devices in one step, like disabling all unused ports. You can download HiVision for free supporting up to 16 managed devices. For more devices you only have to buy a license.