Devices with manually assigned LAN IP addresses receiving different addresses by DHCP, "multiple clients connected through this device"

[josephwit]

I have a GT-AX11000 with latest stock firmware (but from similar threads I think this affects other Asus routers as well).

My iPhone has an IP address manually assigned in the router's LAN-DHCP Server page, but it has lately being assigned a different IP address, by DHCP, although the MAC address shows as the same.

In the Network Map View List, the iPhone shows "2 clients connecting through this device" (Apple Watch?). But the Wi-Fi MAC addresses shown on the iPhone's (and Watch's) own "About" page is different altogether.

There are a few other devices on my network that are receiving incorrect DHCP addresses despite having manual addresses assigned, that do not have mutiple clients connected.

My Vonage box, which is hardwired ethernet to the router, also shows "2 devices connected".

I use my iPhone to connect remotely to my router via VPN, and only specific IP addresses are allowed to connect, so the iPhone MAC address has to be constant.

Manual assignment of an IP address is apparently not reliable.

What the heck is going on? I have seen references to "multiple clients connected" etc in other threads, but no clear explanations.

 

[eibgrad]

As far as the iPhone MAC address, you should be able to disable this changing of the MAC address in the OS (so I'm told).

 

[josephwit]

Thanks, haven't seen that, but that's not the big issue - new IOS with potential for iPhone MAC change is only once a year- I can keep up with that.

The problem is the router ignoring the request for a manually assigned IP for the specific MAC address, and assigning a random one by DHCP to the SAME MAC address.

 

[josephwit]

Looking on my iPhone, I see that I already have "private IP address" enabled for my home Wi-Fi network.

Lower down, it shows "2 IP addresses" - the two clients connected through the router.

They are IPv6 addresses! No idea why they are there or what they mean!

??

 

[raven-au]

Looking on my iPhone, I see that I already have "private IP address" enabled for my home Wi-Fi network.

You must have iOS 14, right?
If so then you need to read up on the new private MAC address feature.
You might be able to turn it off for selected networks, I don't know, and I don't have iOS 14.

 

[josephwit]

OK, so I guess IOS 14 has "private MAC address enabled by default - it was on, and I didn't know about it until now. That explains why my Apple devices have new MAC address since the IOS 14 upgrade.

But I have updated my manual IP assignment list on the router -the router is supposed to assign the IP I request to the new MAC address. That MAC address has not changed again since IOS 14, but the IPs assigned by the router are still variable, not sticking to the list.

And the DHCP IPs ignoring the manual list have occured with some non-Apple devices as well. Definitely my Vonage box, and I think a few others. So the Apple feature is interesting and cool, but not the issue here.

 

[raven-au]

OK, so I guess IOS 14 has "private MAC address enabled by default - it was on, and I didn't know about it until now. That explains why my Apple devices have new MAC address since the IOS 14 upgrade.

But I have updated my manual IP assignment list on the router -the router is supposed to assign the IP I request to the new MAC address. That MAC address has not changed again since IOS 14, but the IPs assigned by the router are still variable, not sticking to the list.

And the DHCP IPs ignoring the manual list have occured with some non-Apple devices as well. Definitely my Vonage box, and I think a few others. So the Apple feature is interesting and cool, but not the issue here.

I'm was able to get stable reserved IP addresses assigned to devices, I had about thirty.

But I also see addresses being sticky, once a device gets an address it appears the DHCP server or the requesting client is unwilling to let the old address go. It's quite frustrating at times but once the address gets set to the reserved one it remains set.

Not sure this is what your seeing, it's just what I've observed.

 

[josephwit]

Nope, the new DHCP IP addresses are random, unrelated to previous assigned ones.

 

[Rassal]

Both IOS 14 and Android 10 gets a new feature called "Randomized MAC address" which is a nightmare if you want to reserve IP to specific devices... you need to disable the Random MAC feature on each Android 10/IOS 14 devices that you want to assign a specific IP address through DHCP reservation. Search about it, i did it on my Android 10 phones, and since i disabled the Random MAC on them they get the reserved IP once the previous lease expire.