iPhone hotspot force IPv4 for connected devices instead of IPv6

That's weird, I have an opposite effect. When I connect my MBP to my iPhone (ipv6 enabled on both) my MBP is assigned a local IP of 192.0.0.2 with a router IP of 192.0.0.1. I'm also assigned an ipv6 ip of fe80::a4cf:99ff:fe00:8364.

DNS IP is also fe80::a4cf:99ff:fe00:8364 which I presume to be my iPhone's IP, but the DNS routing isn't working. I can manually replace that ip with an ipv4 one (8.8.8.8) and everything starts to work.

Alternatively, if I disable ipv6 (networksetup -setv6off Wi-Fi), it defaults to a 172.20.10.7 IP for DNS and it's able to resolve DNS automatically (no manual override needed).

The Hotspot is a Carrier Specific feature. Contact your Carrier (Cellular Service Provider), the agency that issued the SIM / eSIM to you.

See the Pic below the Hotspot is made available based on the Mobile Data selected and the feature that is enabled by the Carrier

Forcing your iPhone's hotspot to provide IPv4 addresses instead of IPv6 addresses involves a few steps:

1. Disable IPv6 on iPhone's Personal Hotspot: Unfortunately, iOS does not have a built-in setting to disable IPv6 on the Personal Hotspot. However, you can try to disable IPv6 globally on your iPhone:
   1. Go to Settings > Cellular > Cellular Data Options > Voice & Data.
   2. Select LTE (if available) or choose a lower option.
2. This might restrict your iPhone to using IPv4 for its data connection, affecting the hotspot as well.
3. If your MacBook Pro connects to a Wi-Fi network with IPv6 preference, it might prioritize IPv6 connections. You can try to prioritize IPv4:
   1. Go to System Preferences > Network.
   2. Connect to Hotspot and click Details (Refer to the pic below).
   3. Under the TCP/IP tab, configure IPv6 settings to "Link-local only" or "Manually"
   4. Apply the changes and reconnect to the iPhone's hotspot.

Remember, disabling IPv6 might limit access to certain services that rely on IPv6. If possible, it's better to let the devices negotiate their own addresses.

No option available to allow ipv4 in iPhone hotspot when you are using jio true 5G, because its bases on cellular network. I too had this same issue. Even customer care not aware about this problem.

Change 5G to LTE, then if you connect hotspot again will see ipv4 assigned.

In my case, I am trying to connect mac m1 to iPhone 15 plus.

I did other way, i took my sim and inserted in 4G device. When i insert the sim back unable to get 5G, but assigned ipv4 in 4G when i check macbook.

I copied router, subnetmask, ip and dns. Later i reached customer care to enable 5G again.

Then checking that ipv4 not assigned after enable 5G. But this time I change DHCP to manual and replaced router, subnet, ip and dns that i copied before. finally it’s working fine with manually assigned ipv4.

remember that you have to remove these manual entries when you are connecting your device to any other router or hotspot.

I wrote a shell script to replace this entries quickly for me.

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you and re-post.

With the limited information that you have provided, It is hard to even guess the problems faced by you. 

You may get faster and better responses to your query by --> Writing an effective Apple Support Commun… - Apple ...

Please re-post with detail so that someone else can help.

1. Is this your corporate iPhone/Mac? Then please contact the system administrator of your corporate
2. If it is your personal device, in that case, do you have any profile installed by your corporate/organisation/enterprise/School Management?
   1. Erase the profile added by you If you have installed a profile on your own --> Install or remove configuration profiles on iPhone - Apple ...
   2. Or please contact the system administrator of the organisation who provided the profile to you
3. If you want to turn on SSL trust for that certificate, go to Settings > General > About > Certificate Trust Settings. Under "Enable full trust for root certificates," turn on trust for the certificate. Apple recommends deploying certificates via Apple Configurator or Mobile Device Management (MDM). --> Trust manually installed certificate profiles in iOS and iPadOS ...

My company uses a VPN which doesn't like IPv6, so our IPv6 is turned off.

sudo networksetup -setv6off Wi-Fi

When attempting to connect to my iPhone's hotspot the iPhone won't connect until IPv6 is turned back on.

sudo networksetup -setv6automatic Wi-Fi

VPN then drops.

Entering this command allowed the hotspot to be stable and the VPN to connect:

sudo networksetup -set6to4automatic Wi-Fi

I'm not quite certain whether the data was slower due to the extra overhead of translation.

You can set IPv6 to “off” on your MacBook but only with terminal:

https://osxdaily.com/2014/04/18/disable-ipv6-mac-os-x/