What is the best way to check for Internet connectivity using .NET?

Question

What is the fastest and most efficient way to check for Internet connectivity in .NET?

Answer 1

I wouldn't think it's impossible, just not straightforward.

I've built something like this, and yes it's not perfect, but the first step is essential: to check if there's any network connectivity. The Windows Api doesn't do a great job, so why not do a better job?

bool NetworkIsAvailable()
{
    var all = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces();
    foreach (var item in all)
    {
        if (item.NetworkInterfaceType == NetworkInterfaceType.Loopback)
            continue;
        if (item.Name.ToLower().Contains("virtual") || item.Description.ToLower().Contains("virtual"))
            continue; //Exclude virtual networks set up by VMWare and others
        if (item.OperationalStatus == OperationalStatus.Up)
        {
            return true;
        }
    }

    return false;
}

It's pretty simple, but it really helps improve the quality of the check, especially when you want to check various proxy configurations.

So:

• Check whether there's network connectivity (make this really good, maybe even have logs sent back to developers when there are false positives to improve the NetworkIsAvailable function)
• HTTP Ping
• (Cycle through Proxy configurations with HTTP Pings on each)