Mac loses web connection after reconnecting to iPhone’s Private Hotspot—how can I repair this?

The answer under may appear over-complicated, however each single line is essential to totally restore community connectivity. Even then, there are some edge circumstances the place the script does not work and I’ve to reboot my machine. If of a greater resolution, please let me know.

1. Export working community settings

Reboot the machine, hook up with the hotspot, after which persist the right community configuration utilizing the next Python script. You may change the WIFI_DEVICE_NAME to ‘iPhone USB’ to persist (and later restore) USB tethering community settings.

import subprocess
import re
import json

WIFI_DEVICE_NAME = "Wi-Fi"

def get_network_info():
    hardware_ports = subprocess.check_output(
        ["networksetup", "-listallhardwareports"], 
        textual content=True
    )

    wifi_match = re.search(
        f"{Hardware} Port: {WIFI_DEVICE_NAME}nDevice: (w+)", 
        hardware_ports
    )
    if not wifi_match:
        elevate Exception("No Wi-Fi interface discovered")
    interface = wifi_match.group(1)

    ifconfig_output = subprocess.check_output(
        f"ifconfig {interface}", 
        shell=True
    ).decode().splitlines()

    ipv4_address = None
    ipv6_addresses = []
    for line in ifconfig_output:
        if "inet " in line:
            ipv4_address = line.break up()[1]
        elif "inet6 " in line:
            ipv6_addresses.append(line.break up()[1].break up("%")[0])

    netstat_output = subprocess.check_output(
        f"netstat -nr | grep default | grep {interface}", 
        shell=True
    ).decode().splitlines()

    ipv4_router = ipv6_router = None
    for line in netstat_output:
        elements = line.break up()
        if len(elements) > 1:
            if ":" not in elements[1]:
                ipv4_router = elements[1]
            else:
                ipv6_router = elements[1].break up("%")[0]

    config = {
        "network_service_name": WIFI_DEVICE_NAME,
        "network_interface_id": interface,
        "ipv4_address": ipv4_address or "Unknown",
        "ipv4_subnet_mask": "255.255.255.0",
        "ipv4_router": ipv4_router or "Unknown",
        "ipv6_primary_address": ipv6_addresses[0] if ipv6_addresses else "Unknown",
        "ipv6_temporary_address": ipv6_addresses[1] if ipv6_addresses[1:] else "Unknown",
        "ipv6_clat46_address": ipv6_addresses[2] if ipv6_addresses[2:] else "Unknown",
        "ipv6_prefix_length": "64",
        "ipv6_router": ipv6_router or "Unknown",
    }

    config_filename = f"network_settings_{interface}.json"
    with open(config_filename, "w") as f:
        json.dump(config, f, indent=2)
    
    print(f"Saved config for {WIFI_DEVICE_NAME} ({interface}) to {config_filename}")

if __name__ == "__main__":
    get_network_info()

The Python script will generate a JSON file with working IPv4 and IPv6 settings inside the identical folder.

2. Restore community settings from the config file, then flip auto/DHCP routing again on

Create one other Python script. Observe that working it requires sudo entry, as a result of altering most community settings on Mac can’t be executed with out sudo privileges.

import subprocess
import json
import time

def run_cmd(cmd, ignore_errors=False):
    attempt:
        subprocess.run(cmd, verify=True)
        print(f"Success: {' '.be a part of(cmd)}")
        return True
    besides subprocess.CalledProcessError as e:
        if not ignore_errors:
            print(f"Failed: {' '.be a part of(cmd)}: {e}")
        return False

def test_network(config_file):
    # Load configuration
    with open(config_file) as f:
        config = json.load(f)

    print("nSetting guide IP configuration...")
    
    # Configure IPv4 settings
    run_cmd([
        "sudo", "networksetup", "-setmanual",
        config["network_service_name"],
        config["ipv4_address"],
        config["ipv4_subnet_mask"],
        config["ipv4_router"]
    ])

    # Replace IPv4 routing
    run_cmd(["sudo", "route", "delete", "default"])
    run_cmd(["sudo", "route", "add", "default", config["ipv4_router"]])

    # Configure IPv6 settings
    run_cmd([
        "sudo", "networksetup", "-setv6manual",
        config["network_service_name"],
        config["ipv6_primary_address"],
        config["ipv6_prefix_length"],
        config["ipv6_router"]
    ])
    
    # Add extra IPv6 addresses
    run_cmd([
        "sudo", "ifconfig", config["network_interface_id"],
        "inet6", "add", config["ipv6_temporary_address"],
        "prefixlen", config["ipv6_prefix_length"]
    ])
    run_cmd([
        "sudo", "ifconfig", config["network_interface_id"],
        "inet6", "add", config["ipv6_clat46_address"],
        "prefixlen", config["ipv6_prefix_length"]
    ])

    # Replace IPv6 routing
    run_cmd(["sudo", "route", "delete", "-inet6", "default"], ignore_errors=True)
    run_cmd([
        "sudo", "route", "add", "-inet6", "default",
        f"{config['ipv6_router']}%{config['network_interface_id']}"
    ])

    print("nWait for 1 second earlier than resetting again to auto/DHCP community configuration...n")
    time.sleep(1)

    print("Resetting to automated configuration...")
    
    # Take away all configured IP addresses
    output = subprocess.check_output(
        f"ifconfig {config['network_interface_id']}", 
        shell=True
    ).decode().splitlines()

    for line in output:
        if "inet " in line:
            run_cmd([
                "sudo", "ifconfig", config["network_interface_id"],
                "inet", line.break up()[1], "take away"
            ])
        elif "inet6 " in line:
            run_cmd([
                "sudo", "ifconfig", config["network_interface_id"],
                "inet6", "del", line.break up()[1]
            ])

    # Reset to automated configuration
    run_cmd(["sudo", "networksetup", "-setdhcp", config["network_service_name"]])
    run_cmd(["sudo", "networksetup", "-setv6automatic", config["network_service_name"]])

if __name__ == "__main__":
    import sys
    test_network(sys.argv[1])

When tethering stops working, execute the script, passing the generated config file title into it:

python3 load_working_network_settings.py network_settings_en0.json

Voila! Your web entry ought to (hopefully) be restored now.