Ipad Privacy warning

[#1]

They are different things.

The WiFi address is not the same as the IPv4 address issued in the DHCP pool. The WiFi address is a machine identifier, which is unique to your device, and usually remains the same between different networks. The DHCP allocated address is just a device address for a particular network.

The ‘private’ WiFi address that Apple implements here is an attempt to add another level of security when using unknown or public WiFi services. It’s not necessary in a home environment, but could be of benefit in public services. It’s set individually for each network you have stored, so you can enable or disable for each of them.

The IPv4 address is supplied by a DHCP server in a router, and can change at any time. Usually the pool will be from, say, ‘02’ and ‘254’. ‘01’ is normally reserved for the router itself.

If you try to use a fixed IP, then you need to either turn off the DHCP server, and allocate all IPs manually. Or you can change the pool range, and split between auto and manual allocation.

On some routers, you can also fix the IP in the router, instead of the device. This is how I’ve done it myself. I have the DHCP pool set to the range 100-254. Then I fix my home devices in the 2-99 range. Any temporary devices (I.e. for visitors), get an auto allocated IP. Then I set each device in the router to use a fixed IP.

To be honest, this was all in attempts to fix issues the Apple HomePods have when used as a stereo pair on an AppleTV. It seems to have done the job.

cheers

[#2]

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@Wildroverandy wrote:

They are different things.

The WiFi address is not the same as the IPv4 address issued in the DHCP pool. The WiFi address is a machine identifier, which is unique to your device, and usually remains the same between different networks. The DHCP allocated address is just a device address for a particular network.

*Didn't say it was. On our Apple devices the WiFi address is the MAC Address.

[#3]

Moderator's note(s):

Thread moved from Broadband to Tech Help.

[#4]

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@Champnet wrote:

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@Wildroverandy wrote:

They are different things.

The WiFi address is not the same as the IPv4 address issued in the DHCP pool. The WiFi address is a machine identifier, which is unique to your device, and usually remains the same between different networks. The DHCP allocated address is just a device address for a particular network.

*Didn't say it was. On our Apple devices the WiFi address is the MAC Address.

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Indeed so, yes, what Apple have named as the WiFi address is of course just the MAC address.

[#5]

... and DHCP allocates an IP address (and remembers the allocation) based on a device's MAC address.  Therefore a device which keeps changing its MAC address is going to chomp through IP address leases, potentially at an alarming rate, whilst making static IP address allocation (via DHCP) a tad difficult.

This has the hallmarks of a solution in search of a problem. The practicality of tracking a device across different WiFi networks based on its MAC address seems technically far more complex than simply dropping a cookie onto the device, which will do exactly the same!

[#6]

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@Townman wrote:

... and DHCP allocates an IP address (and remembers the allocation) based on a device's MAC address.  Therefore a device which keeps changing its MAC address is going to chomp through IP address leases, potentially at an alarming rate, whilst making static IP address allocation (via DHCP) a tad difficult.

This has the hallmarks of a solution in search of a problem. The practicality of tracking a device across different WiFi networks based on its MAC address seems technically far more complex than simply dropping a cookie onto the device, which will do exactly the same!

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Yes, it does seem to be like that, and a little puzzling that it’s meant to increase security on mobile devices, but is not included on a MacBook!

However, it does not ‘eat’ IP addresses in normal use. It basically functions by allocating a ‘private’ WiFi (MAC) address for a particular location, so once allocated it doesn’t change for a saved WiFi network. It only changes for certain circumstances, such as a reset, or system reinstall. It only creates one address for each network otherwise, and keeps the original machine address hidden.

As you say, it is generally regarded as a solution in search of a problem (perhaps it just hasn’t been exploited yet - who knows :-))

cheers 

[#7]

@Wildroverandy  For info: Just tested your comments about private Wi-Fi settings on my iPad.

The device will retain IP & MAC addresses until it’s powered down then there’s a new MAC address and the IP address moves on by one.

[#8]

@Wildroverandy 

Seems that @Champnet has suggested an explanation for my observations / experience wherein I see lots of IP address leases for (what I think is) the same device having a different MAC address.

[#9]

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@Townman wrote:

@Wildroverandy 

Seems that @Champnet has suggested an explanation for my observations / experience wherein I see lots of IP address leases for (what I think is) the same device having a different MAC address.

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Yes, you seem to have an issue there. That's not supposed to happen. According to this:

https://support.apple.com/en-us/102076

It should be remembering the Private Wifi Address, unless it's been more than 6 weeks of not using that network, or you use the 'Forget Network' button for iOS15. If you use the network regularly, then it should be remembering the Private address.

Which is pretty much what I got when I did use it, along with the same IP being allocated too - indeed, it seemed difficult to get a different IP address when I tried.

At the moment, I use the 'Always use this IP address' feature too, and set all my normal home devices to keep their IP addresses (this was more of a troubleshooting thing with the HomePods dropping out occasionally).

[#10]

@Wildroverandy 

Normal use : (fixed IP device 192.168.1.190)

Private Wi-Fi : (DHCP range for non fixed IP devices 192.168.1.210-230)

Private Wi-Fi following restart :

[#11]

That’s definitely weird, and not expected behaviour.

I’v just tried the same here on my iPhone, and got the same ‘private’ address across a restart, and the same IP address too.

Turning off ‘’Private…’ also gets me the same IP address across restarts.

I turned off the fixed mode for this.

[#12]

@Wildroverandy  I’ll try my iPhone tomorrow.

[#13]

@Wildroverandy  Bit more Info :

His 'n Hers identical iPad Air 2 Private Wi-Fi enabled.

Following re-boot His MAC & IP changed, Hers didn't.

His 'n Hers identical iPhone SE Private Wi-Fi enabled.

Following re-boot Her MAC & IP changed, His didn't.

Illogical.......

[#14]

@Champnet 

I don't use have ipads/iphones to check, but do they have the option described by this Android user?

https://community.plus.net/t5/My-Router/Hub2-and-Android-Wifi-Internet-connectivity/m-p/1985231/high... 

[#15]

@RobPN  Thanks but there dosen’t seem to be an option to randomised the MAC address, and the settings of both iPads are identical.

Although strange this is not causing a problem.

** just come across this article, I don’t fully understand but It seem to suggest differences maybe caused by an app using geolocation…

https://support.apple.com/en-gb/guide/security/secb9cb3140c/web