Ethernet ports do not stop communicating when being disabled via "Admin State" attribute (certification issue)

With Ethernet Link attribute 9 (Admin State) one can disable one of the two ethernet ports of the device. This port is supposed to stop communicating once disabled.

Under certain conditions a disabled port does not stop communicating. Frames are still received and processed and frames are still forwarded to the other ethernet port.

Steps to reproduce:

Setup:

Port Configuration:

Port B: 100MBit/Half Duplex
Port C: Auto-Neg
Port D, E: Auto-Neg

Steps:

1. All devices are powered and are connection to each other as illustrated above.
2. Port are configured as described above (port configuration)
3. The EtherNet/IP Device (EIP-Device) has both ports set to "Enabled" in admin state attribute for instance 1 and 2 (Port C and Port D, respectively).
4. Both ports of the EIP-Device have a link (link LED).
5. Via the PC set the admin state attribute 9 of instance 1 to value 2 "disabled".
6. The link LED oth Port C will go off and again on after some seconds.
7. Send two conflicting ARP frames to the EIP-Device within 1 seconds.
8. The Eip Device will go into an ACD conflict state (Network Status LED: static red, Module Status LED: flashing red)

The EIP-Device must not react to the ARP frames, as Port C is disabled at that moment.
The behavior is the same for Port D (Ethernet Link instance 2).

In a DLR network the disabled port also forwards frames.