CODEWITHSUNDEEP
c#.net-4.5ping
NoBullMan
NoBullMan

Reputation: 2184

Ping causes unhandled exception

I have a list of server IP addresses and in part of my application, before sending a request to each server, I ping it. When I test it through VS 2012, part way through, it stops and displays a page in VS, saying "Unable to connect to the remote server". I have the ping in a try-catch but it doesn't fall into the exception section; it just dies executin ping.send(). Some of the other pings time out and I catch those and display proper message. When I check the exception trace (below), it says:"No connection could be made because the target machine actively refused it". Is there any way to catch and handle this rather stop the program from running?

This is (partial) ping code:

public static string PingServer(string host)
{
    PingOptions options = new PingOptions();
    options.DontFragment = true;
    Ping p = new Ping();
    PingReply reply = null;
    string NetworkMessage = string.Empty;

    try
    {
        string data = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
        byte[] buffer = Encoding.ASCII.GetBytes(data);
        int timeout = 120;
        Console.WriteLine(host);
        reply = p.Send(host, timeout, buffer, options);

This is the exception trace:

System.Net.WebException was unhandled
  HResult=-2146233079
  Message=Unable to connect to the remote server
  Source=System
  StackTrace:
       at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
       at PASSCrawlerNS.PASSCrawler.GetResponseCallback(IAsyncResult ar) in c:\Users\blah\Documents\Visual Studio 2012\Projects\test\test\Program.cs:line 102
       at System.Net.LazyAsyncResult.Complete(IntPtr userToken)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Net.ContextAwareResult.Complete(IntPtr userToken)
       at System.Net.HttpWebRequest.SetResponse(Exception E)
       at System.Net.ConnectionReturnResult.SetResponses(ConnectionReturnResult returnResult)
       at System.Net.Connection.CompleteConnectionWrapper(Object request, Object state)
       at System.Net.PooledStream.ConnectionCallback(Object owningObject, Exception e, Socket socket, IPAddress address)
       at System.Net.ServicePoint.ConnectSocketCallback(IAsyncResult asyncResult)
       at System.Net.LazyAsyncResult.Complete(IntPtr userToken)
       at System.Net.ContextAwareResult.Complete(IntPtr userToken)
       at System.Net.Sockets.Socket.ConnectCallback()
       at System.Threading._ThreadPoolWaitOrTimerCallback.PerformWaitOrTimerCallback(Object state, Boolean timedOut)
  InnerException: System.Net.Sockets.SocketException
       HResult=-2147467259
       **Message=No connection could be made because the target machine actively refused it** 56.245.253.10:80
       Source=System
       ErrorCode=10061
       NativeErrorCode=10061
       StackTrace:
            at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult)
            at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)
   InnerException:

When I manually ping this server (56.245.253.10), it replies.

Upvotes: 0

Views: 2308

Answers (1)

Bibaswann Bandyopadhyay
Bibaswann Bandyopadhyay

Reputation: 3547

If you just want to test if the server is active by ping method, you can try this

    private async Task<bool> PingHost(string ip)
    {
        bool pingable = true;
        Ping mypinger = new Ping();
        try
        {
            PingReply reply = mypinger.Send(ip);
            pingable = (reply.Status == IPStatus.Success) ? true : false;
        }
        catch (PingException)
        {
            return false;
        }
        return pingable;
    }

It runs asynchronously so doesn't block your main thread. You have to call it with await operator from another async method

Upvotes: 1

Related Questions