Check Website is Online or Offline using C# and VB.Net in ASP.Net

Hi Gln,

Refer below sample.

HTML

<asp:Label ID="lblMessage" runat="server" />

Namespaces

C#

using System.Net;

VB.Net

Imports System.Net

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    bool check = CheckForInternetConnection();
    if (check == true)
    {
        Response.Redirect("https://www.aspsnippets.com/");
    }
    else
    {
        lblMessage.Text = "No internet";
    }
}

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

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    Dim check As Boolean = CheckForInternetConnection()
    If check = True Then
        Response.Redirect("https://www.aspsnippets.com/")
    Else
        lblMessage.Text = "No internet"
    End If
End Sub

Public Shared Function CheckForInternetConnection() As Boolean
    Try
        Using client = New WebClient()
            Using client.OpenRead("https://www.aspsnippets.com/")
                Return True
            End Using
        End Using
    Catch
        Return False
    End Try
End Function