An elegant / simple way to check whether internet is available or not.

Question

I did a quick search on how to check whether Internet is available or not. Most of them talked about making InterOp calls to wininet.dll.

One of the answers pointed towards System.Net.NetworkInformation namespace. Exploring the namespace I found a class Ping which could be used to pinging to our servers from code, and checking whether server is available or not.

What I want to ask is how this solution compares to other solutions?

Ping soPing = new Ping();
var soPingReply = soPing.Send("www.stackoverflow.com");
if (soPingReply.Status != IPStatus.Success)
{
    // SO not available
}

Answer 1

Try this:

[DllImport("wininet.dll")]
private extern static bool InternetGetConnectedState(out int Description, int ReservedValue);

//Creating a function that uses the API function...
public static bool IsConnectedToInternet()
{
    int Desc;
    return InternetGetConnectedState(out Desc, 0);
}

Answer 2

Network connectivity has nothing to do with the ability to ping some (random?) site. If you're behind a firewall or the destination is that ping (or the response) may well be blocked when actual traffic isn't.

And even if that ping works, there's no guarantee that connection will still be up by the time you want to make the actual request. So best to just do the actual request and make sure you handle any network errors that may occur correctly.

Answer 3

How long does it try and ping for? Does it matter if your app locks up for 30secs while it does so?

Do you have an internet connection but it's temporarily down?

Is it the internet that's down or is the SO site?

What if the local firewall blocks ping?