Check Whether Internet Connection Is Available with C#

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

public static bool CheckForInternetConnection(int timeoutMs = 10000, string url = null)
{
    try
    {
        url ??= CultureInfo.InstalledUICulture switch
        {
            { Name: var n } when n.StartsWith("fa") => // Iran
                "http://www.aparat.com",
            { Name: var n } when n.StartsWith("zh") => // China
                "http://www.baidu.com",
            _ =>
                "http://www.gstatic.com/generate_204",
        };

        var request = (HttpWebRequest)WebRequest.Create(url);
        request.KeepAlive = false;
        request.Timeout = timeoutMs;
        using (var response = (HttpWebResponse)request.GetResponse())
            return true;
    }
    catch
    {
        return false;
    }
}

C# checking Internet connection

a little shorter version:

public static bool CheckForInternetConnection()
{
    try
    {
        using (var client = new WebClient())
        using (var stream = client.OpenRead("http://www.google.com"))
        {
            return true;
        }
    }
    catch
    {
        return false;
    }
}

Another option is:

Ping myPing = new Ping();
String host = "google.com";
byte[] buffer = new byte[32];
int timeout = 1000;
PingOptions pingOptions = new PingOptions();
PingReply reply = myPing.Send(host, timeout, buffer, pingOptions);
if (reply.Status == IPStatus.Success) {
  // presumably online
}

You can find a broader discussion here

check internet connection available or not in c#

You can check whether internet is available or not like this:

ConnectionProfile internetConnectionProfile = Windows.Networking.Connectivity.NetworkInformation.GetInternetConnectionProfile();
            if (internetConnectionProfile == null)
            {
               //logic ....
            }

            if (internetConnectionProfile != null)
            {
                this.IsInternetAvailable = internetConnectionProfile.GetNetworkConnectivityLevel() ==
                                           NetworkConnectivityLevel.InternetAccess;

                if (internetConnectionProfile.NetworkAdapter.IanaInterfaceType != 71)// Connection is not a Wi-Fi connection. 
                {
                    var isRoaming = internetConnectionProfile.GetConnectionCost().Roaming;

                    //user is Low on Data package only send low data.
                    var isLowOnData = internetConnectionProfile.GetConnectionCost().ApproachingDataLimit;

                    //User is over limit do not send data
                    var isOverDataLimit = internetConnectionProfile.GetConnectionCost().OverDataLimit;
                    IsWifiConnected = true;

                }
                else //Connection is a Wi-Fi connection. Data restrictions are not necessary. 
                {
                    IsWifiConnected = true;

                }
            }

How to check the Internet connection with .NET, C#, and WPF

In the end I used my own code:

private bool CheckConnection(String URL)
{
    try
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
        request.Timeout = 5000;
        request.Credentials = CredentialCache.DefaultNetworkCredentials;
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();

        if (response.StatusCode == HttpStatusCode.OK)
            return true;
        else
            return false;
    }
    catch
    {
        return false;
    }
}

An interesting thing is that when the server is down (I turn off my Apache) I'm not getting any HTTP status, but an exception is thrown. But this works good enough :)

How do I check for a network connection?

You can check for a network connection in .NET 2.0 using GetIsNetworkAvailable():

System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable()

To monitor changes in IP address or changes in network availability use the events from the NetworkChange class:

System.Net.NetworkInformation.NetworkChange.NetworkAvailabilityChanged
System.Net.NetworkInformation.NetworkChange.NetworkAddressChanged

How to check internet connectivity type in Universal Windows Platform

1. Check Internet Connection Availability

To check whether any network connection is established or not use GetIsNetworkAvailable method of NetworkInterface class.

bool isNetworkConnected = NetworkInterface.GetIsNetworkAvailable();

GetIsNetworkAvailable() -

Summary: Indicates whether any network connection is available.

Returns: true if a network connection is available; otherwise, false.

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2. Check Internet Connection Availability via WWLN (WiFi)

To check whether internet connected via WWAN use IsWlanConnectionProfile property of ConnectionProfile class

ConnectionProfile InternetConnectionProfile = NetworkInformation.GetInternetConnectionProfile();
bool isWLANConnection = (InternetConnectionProfile == null)?false:InternetConnectionProfile.IsWlanConnectionProfile;

IsWlanConnectionProfile
Summary: Gets a value that indicates if connection profile is a WLAN (WiFi) connection. This determines whether or not
WlanConnectionProfileDetails is null.

Returns: Indicates if the connection profile represents a WLAN (WiFi) connection.

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3. Check Internet Connection Availability via WWAN (Mobile)

To check whether internet connected via WWAN use IsWwanConnectionProfile property ofConnectionProfile class

ConnectionProfile InternetConnectionProfile = NetworkInformation.GetInternetConnectionProfile();
bool isWLANConnection = (InternetConnectionProfile == null)?false:InternetConnectionProfile.IsWwanConnectionProfile;

IsWwanConnectionProfile
Summary: Gets a value that indicates if connection profile is a WWAN (mobile) connection. This determines whether or not WwanConnectionProfileDetails is null.

Returns: Indicates if the connection profile represents a WWAN (mobile) connection.

Reference
Hippiehunter Answer

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4. Check Metered network

To check whether Internet reachable via a metered connection or not, use GetConnectionCost method on NetworkInterface class.

var connectionCost = NetworkInformation.GetInternetConnectionProfile().GetConnectionCost();
if (connectionCost.NetworkCostType == NetworkCostType.Unknown 
        || connectionCost.NetworkCostType == NetworkCostType.Unrestricted)
{
    //Connection cost is unknown/unrestricted
}
else
{
   //Metered Network
}

Reference (More detailed answer here)

1. How to manage metered network cost constraints - MSDN

2. NetworkCostType Enum - MSDN

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5. Manage network availability changes

To sense the significant network availability changes, use eventNetworkStatusChanged of NetworkInformation class

// register for network status change notifications
 networkStatusCallback = new NetworkStatusChangedEventHandler(OnNetworkStatusChange);
 if (!registeredNetworkStatusNotif)
 {
     NetworkInformation.NetworkStatusChanged += networkStatusCallback;
     registeredNetworkStatusNotif = true;
 }

async void OnNetworkStatusChange(object sender)
{
    // get the ConnectionProfile that is currently used to connect to the Internet                
    ConnectionProfile InternetConnectionProfile = NetworkInformation.GetInternetConnectionProfile();

    if (InternetConnectionProfile == null)
    {
        await _cd.RunAsync(CoreDispatcherPriority.Normal, () =>
        {
            rootPage.NotifyUser("Not connected to Internet\n", NotifyType.StatusMessage);
        });
    }
    else
    {
        connectionProfileInfo = GetConnectionProfile(InternetConnectionProfile);
        await _cd.RunAsync(CoreDispatcherPriority.Normal, () =>
        {
            rootPage.NotifyUser(connectionProfileInfo, NotifyType.StatusMessage);
        });
    }
    internetProfileInfo = "";
}

References
Check Internet Connectivity - developerinsider.co

How to manage network connection events and changes in availability - MSDN

How to retrieve network connection information- MSDN

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Hope it helpful to someone.

How to check if internet connectivity available or not in C#

Why not just try to perform a very cheap query on the database? Indeed, you could create a stored procedure for exactly this purpose - it might even give some version information back, etc.

After all, the important thing isn't whether a ping works, or whether the client can go to other machines: the important thing is whether you can talk to the database or not. So test exactly that.

As for what error message is presented to the user - surely that's under your control, so make sure you give appropriate information.

Checking network status in C#

If you just want to check if the network is up then use:

bool networkUp
    = System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable();

To check a specific interface's status (or other info) use:

NetworkInterface[] networkCards
    = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces();

To check the status of a remote computer then you'll have to connect to that computer (see other answers)

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