Neillans

Q: Two MAC address on WiFi?

Why does my iPad air appear to have two different MAC addresses?

 

I'm seeing entries for two distinct MAC's in my DHCP server database for a single iPad Air...

 

11,01/27/14,00:02:49,Renew,192.168.0.1,Andys-iPad.yyy.local,CC785FB1612F,,407925 7579,0,,,,,,,,,0

11,01/27/14,00:07:49,Renew,192.168.0.2,Andys-iPad.yyy.local,B8E85679AF81,,157309 0531,0,,,,,,,,,0

 

Andy

Posted on Jan 27, 2014 1:01 PM

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Q: Two MAC address on WiFi?

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  • by lizdance40,

    lizdance40 lizdance40 Jan 27, 2014 1:05 PM in response to Neillans
    Level 4 (2,382 points)
    Jan 27, 2014 1:05 PM in response to Neillans

    Totally normal.   Like most of us, you have more than one device using wifi and probably have a dual signal wifi that can accomodate many devices.  Unless devices have static IP addresses, they will pick up on any avaiable IP in your list.

  • by Neillans,

    Neillans Neillans Jan 27, 2014 1:21 PM in response to lizdance40
    Level 1 (0 points)
    Jan 27, 2014 1:21 PM in response to lizdance40

    The only way that would make sense is if the Air carried two seperate Wifi modules; one for 2.4Ghz and one for 5Ghz. However, if that were the case, they would be required to publish the MAC addresses (FCC requirement).

    As it is, only one of the MAC addresses is actually visible on the Air in the About section.

     

    I'm well aware of how DHCP functions; I'm just curious as to why a single device is requesting an IP on the network using two (obviously different) MAC addresses. I've confirmed it is a specific device(s) - the airs - doing this, as I've tested this on a isolated test network I have.

  • by thanos318,

    thanos318 thanos318 Sep 5, 2016 11:01 AM in response to Neillans
    Level 1 (0 points)
    Sep 5, 2016 11:01 AM in response to Neillans

    <Image Edited for Personal Information>

    192.168.1.185 appears twice.. Any idea?

  • by Mikeejo,

    Mikeejo Mikeejo Sep 1, 2016 2:06 PM in response to Neillans
    Level 1 (4 points)
    Sep 1, 2016 2:06 PM in response to Neillans

    I Discovered the exact same thing using "Fing" ( same issue on my home router and work router ), and after some searching around, I discovered that the other WiFi Mac address was not the Blutooth Mac address like so many think it is, but is really the WiFi Mac address  from my old iPhone 4S ( I upgraded to the iPhone SE).

     

    When I had brought the new SE home, I just did a "Restore from Backup", and apparently, it brought with it the old Mac Address from my 4S!

     

    I know it's from my 4S because I keep a list of all my Mac addresses.

     

    Now the problem is how to eliminate the old Mac address.

  • by Mikeejo,

    Mikeejo Mikeejo Sep 3, 2016 5:33 PM in response to Mikeejo
    Level 1 (4 points)
    Sep 3, 2016 5:33 PM in response to Mikeejo


    Well, I've discovered the problem. Apparently, Fing remembers all Mac addresses it has seen for a particular Router. It sort of keeps an image of all devices that have been previously connected to it. It seems here that it paired my iPhone device name with two different Mac addresses, my new current SE, and my old one ( the 4s). I used the exact device name for both. I had also assigned the new iPhone the exact static IP address on my router.

     

    The solution was to remove the mac address and static IP address for my old 4S from the router and assign it to the mac address of my new SE, and then go into Fing, rescan.

     

    Now the new mac address showed as the primary (the SE), an the old mac address and device name were greyed out.

     

    I just deleted the old greyed out one, and now everything is fine.

     

    NOTE: You can delete greyed out devices in the Fing app interface,

  • by Lawrence Finch,

    Lawrence Finch Lawrence Finch Sep 3, 2016 6:26 PM in response to Mikeejo
    Level 8 (37,837 points)
    Mac OS X
    Sep 3, 2016 6:26 PM in response to Mikeejo

    Thanks for following up; the problem was Fing, not the phone. I hadn't noticed that "feature" of Fing, but now that I look I see the same thing.

     

    I was going to mention an alternate possibility: When a iPhone is searching for a network it publishes a bogus MAC address so the phone can't be tracked by its address unless you actually connect to the network. If you tap to connect it switches to the correct MAC address.

  • by Mikeejo,

    Mikeejo Mikeejo Sep 4, 2016 10:56 AM in response to Lawrence Finch
    Level 1 (4 points)
    Sep 4, 2016 10:56 AM in response to Lawrence Finch


    Yes exactly, the problem is "Fing" and not the router or the phone. The same thing happens on the router at work. The interesting thing will be, if I delete the device (in Fing) when I'm at work, and then re-scan, will the old mac address be eliminated.

     

    I'm not an administrator there, so I'll just have to see.