Resetting MAC address to NIC real address.

  • I had a pfSense box where I spoofed the MAC, well I removed the MAC from the field thinking it would go back to the real NICs MAC, rebooted, still spoofed, since I didnt need the config on this box anymore I factory reset pfSense, to my dismay it is still showing to spoofed MAC.

    How from shell can I clear this spoofed MAC, or must pfSense be completely reloaded?

  • @Napsterbater

    I searched using my favorite search engine - duckduckgo - and found some possibilities for you.

    Hope they provide the info you need.

    Note you may have to open the box and read the label of the NIC to get it's factory MAC.

  • I could find how to Set the MAC, I never found how to delete the set mac to let it revert to default.

    I reloaded pfSense, still had the spoofed MAC.

    Apparently even in the BIOS Network boot screen for the NIC it was showing the spoofed MAC.

    I ended up having to pull the CMOS battery to get it to revert..

    Not sure how setting the MAC in pfsense caused it to effect even the NICs network boot rom.

  • Glad you got it fixed, and sorry the ideas didn't help.

    My thoughts are then that pfSense may need a MAC address in the setting, and if there isn't one, it uses the last known MAC, maybe by inputting  another MAC, spoofed or real, it may change.

  • Sorry for reviving an old post but I just ran into this same issue on my newly purchased SG-4860 running 2.3.4-RELEASE-p1

    This doesn't seem very intuitive & seems like it could potentially cause some unexpected & problematic behavior if someone deletes a LAGG & then tries to use the ports individually without being aware of this "functionality".

    The reason being, when you assign interfaces to a LAGG, they all are given the same MAC. The potential problem (and definitely unexpected behavior) is that after removing the interfaces from the LAGG they all retain the same shared MAC!

    In the attached screenshot you'll notice that igb4 & igb5 have the same MAC. That's because they were assigned to the same LAGG at one point & then removed. This was definitely not expected behavior & took me a while to figure out why it had happened since I had never manually set a spoofed MAC on the interfaces directly.

    Is this behavior really functioning as intended?

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