Iphone on home network - Multiple non-persistent (and sometimes duplicate) faked MAC addresses causing problems on wifi

For your home router, when connected go to Settings/Wi-Fi and turn off Private Wi-Fi Address. This is a feature so commercial hotspots can’t track your phone, but you clearly don’t need it for your own router.

That said, an iPhone connecting to a given router will always use the same fake IP address with that router, unless you Reset Network Settings on the phone or change some setting on the router.. If yours isn’t something very strange is happening. Either the ROUTER has a similar feature and also uses fake IP addresses, or there is something wrong with your iPhones or your router.

No guarantees, but worth a try if you have not already done this:

Turn off Private Address on the phone

Set up your router to assign a fixed static IP address for the phone using the Wi-Fi Address for the phone

Settings > General > About > Wi-Fi Address

Do the same for other phones

FrogtoneMcSpartin wrote:

I'm experiencing home network issues because of Multiple, duplicated, and most importantly, non-persistent MAC addresses show-up on my Netgear RAX45's device list. This has been traced-back to my (and my wife's) iphone.

Troubleshooting would indicate that this is happening likely due to one of new privacy functions, in the wifi settings of the Iphone:

The Private Address option, and/or the I-Cloud Private Relay.

How do these settings actually function on a network?

You are correct that the "culprit" is Apple's Private Address option. Basically, this is just a form of MAC address spoofing. I see the same results as you, with my UniFi-based network. These random MAC addresses appear in my client list on the UniFi Controller.

iCloud Private Relay, is not really involved here as it redirects outbound DNS requests to Apple-provided DNS servers.

Is there a way to "force" one persistent (albeit- faux) MAC address on my iphone?

No, as that would defeat the purpose (security) of this feature.

These hundreds of MAC addresses tend to persist in the router's previously-connected device list, therefore appears to cause memory issues leading to network performance loss.

FWIW, I don't have this issue with my UniFi system. Appears that Netgear doesn't have a means to better manage their router's memory.

While Private relay and Private MAC Addressing isn't something that's absolutely needed at home, these are on by default. This can really cause problems due to the hundreds of "old devices" that my router must remember.

Why Apple decided to configure Private Addressing to be enabled by default, I can only guess that Apple figures most folks would want this "security" feature enabled ... or, most likely, to simplify the user's experience with iPhone security ... and Private Relay is not enabled by default. You would have to elect to purchase iCloud+ service to have it available to you.

As far as suggestion, I believe Bob Timmons has already provided that one for you. Alternately, you can consider getting a prosumer or business grade router where you have more control over it. Apple's design decisions will not be the only vendor to contend with on these type of issues.