Internet Checker

InternetChecker.cs

using System.Collections;
using System.Collections.Generic;
using System.Threading.Tasks;
using UnityEngine;
using Ping = UnityEngine.Ping;

public class InternetChecker : SingletonBehaviour<InternetChecker>
{
    private readonly List<string> _theListOfIPs = new() { "4.2.2.4", "www.google.com" };
    private int _counter;
    [SerializeField] private float Timeout;

    public async Task<bool> CheckNetwork()
    {
        var internetPossiblyAvailable = Application.internetReachability switch
        {
            NetworkReachability.ReachableViaCarrierDataNetwork => true,
            NetworkReachability.ReachableViaLocalAreaNetwork => true,
            NetworkReachability.NotReachable => false,
            _ => false
        };

        if (!internetPossiblyAvailable)
        {
            return false;
        }

        return await CheckPing();
    }

    private async Task<bool> CheckPing()
    {
        _counter = 0;
        var tcs = new TaskCompletionSource<bool>();
        StartCoroutine(Ping(tcs));
        await tcs.Task;
        return tcs.Task.Result;
    }

    private IEnumerator Ping(TaskCompletionSource<bool> task)
    {
        var ping = new Ping(_theListOfIPs[_counter]);
        while (!ping.isDone || Timeout > 0)
        {
            Timeout -= 0.1f;
            yield return new WaitForSeconds(0.1f);
        }

        if (!ping.isDone)
        {
            _counter++;
            if (_counter >= _theListOfIPs.Count)
            {
                task.SetResult(false);
            }
            else
                StartCoroutine(Ping(task));
        }
        else
        {
            task.SetResult(true);
        }
    }
}

InternetManager.cs

using System;
using UnityEngine;

public class InternetManager : MonoBehaviour
{
    [SerializeField] private InternetChecker InternetChecker;

    private async void Start()
    {
        var isOnline = await InternetChecker.CheckNetwork();
        Debug.Log($"Is online: {isOnline}");
    }
}