• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 98 subscribers
  • Views 270 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

[FAQ] Where do the MAC addresses for AM62x and AM64x come from? How do I change the MAC addresses?

AM6442: Regarding MAC Address Usage for Ethernet Communication Between Boards

O.H
Mastermind 7305 points

Part Number: AM6442

Hi experts,

My customer are planning to use the AM6442 for Ethernet communication between boards inside customer's production equipment. The Ethernet interfaces on the Sitara device are intended only for communication between boards within the equipment, and are not expected to be connected to any external network or external devices.

Q1:
In this case, although the equipment itself is a mass-produced product, do we still need to use our own company-assigned MAC addresses with consideration for operation in products released outside the company?

Based on this E2E discussions, we are planning to configure the MAC addresses as follows:

  • eth0: Use the TI-programmed MAC address stored in the device.
  • eth1: Use the TI-programmed MAC address incremented by one (+1).

Could you please advise whether there are any concerns or recommended practices regarding this approach?

Best regards,
O.H

  • 0
    TI__Genius 16660 points

    Hello Hiromichi Otomo-san,

    Thank you for reaching out to the SITARA MPU Hardware Applications support team.

    Let me internally discuss in TI. I may need to forward your query to another team / expert.

    I will try to get back with a response in a day or two.

    Thank you for your patience !

    Best Regards,

    Anastas Yordanov

  • 0 in reply to Anastas Yordanov
    TI__Genius 16660 points

    Hello Hiromichi Otomo-san,

    I will let our SITARA Ethernet MAC controller hardware expert - Paul further comment.

    Please expect that some delay may be possible depending on his availability / workload.

    Thank you !

    Best Regards,

    Anastas Yordanov 

  • +1 in reply to Anastas Yordanov
    TI__Guru 64995 points

    I have confirmed TI only assigns a single MAC Address from the TI pool of MAC addresses to each AM64x device. Therefore, you should not use the approach of assigning the TI-programmed MAC address incremented by one (+1) to your second ethernet port as proposed above. 

    The TI-programmed MAC address incremented by one (+1) will be programmed into another TI device and this may cause problems if it is connected in the same network.  We share the TI pool of MAC addresses across many TI devices, so the MAC address in question may be assigned to another AM64x device or any one of many TI devices. TI MAC addresses are pulled from an internal repository in real time as the device is goes through its test flow.  Other TI devices may be going through a parallel test flow at the same time, where each test flow is pulling MAC addresses from the same pool of MAC addresses.  This means there is a chance the assignment of TI MAC addresses will get interleaved across multiple TI devices.

    Regards,
    Paul

  • 0 in reply to peaves
    Mastermind 7305 points

    Hi Paul,

    Thank you for your reply.

    Q2: Is the following understanding correct?
    Since the Sitara Ethernet interfaces are used only for internal communication within the equipment and are not intended to be connected to any external devices or networks, it is not necessary to use MAC addresses obtained and managed by the end customer. This is based on the understanding that the customer is aware of, and accepts, the potential risk of MAC address conflicts within the internal network.

    Q3: As an alternative approach, would it be acceptable to use software-generated MAC addresses as Locally Administered Addresses (LAA)?
    For example, we are considering generating MAC addresses in software and setting the U/L (Universal/Local) bit to indicate a locally administered address. Would TI consider this to be an appropriate approach? If there are any other recommended methods or best practices for handling additional Ethernet port MAC addresses in this type of application, please let us know.

    Best regards,
    O.H

  • +1 in reply to O.H
    TI__Guru 64995 points

    Answers to these questions are specific to how the customers product will be implemented within a network. TI does not fully understand all of the connection topology options for the product and TI does not have any control over how the product may be connected within a network by various users. Therefore, these questions are beyond the scope of what TI can answer. The customer needs to understand the implications of not assigning unique MAC addresses to their Ethernet ports.

    They shall never use any MAC address from the TI pool of MAC addresses for any Ethernet port that was not assigned by TI to the processor.  We do not want to get pulled into an issue where someone finds multiple TI MAC addresses being used in a network.

    Regards,
    Paul

  • 0 in reply to peaves
    Mastermind 7305 points

    Hi Paul,

    Thank you for your reply. I understood.

    Best regards,
    O.H