Using ping in c#

Question

When I Ping a remote system with Windows it says there is no reply, but when I ping with c# it says success. Windows is correct, the device is not connected. Why is my code able to successfully ping when Windows is not?

Here is my code :

Ping p1 = new Ping();
PingReply PR = p1.Send("192.168.2.18");
// check when the ping is not success
while (!PR.Status.ToString().Equals("Success"))
{
    Console.WriteLine(PR.Status.ToString());
    PR = p1.Send("192.168.2.18");
}
// check after the ping is n success
while (PR.Status.ToString().Equals("Success"))
{
    Console.WriteLine(PR.Status.ToString());
    PR = p1.Send("192.168.2.18");
}

Hesler

Check out the following example posted at the bottom of this page when you click on the MSDN Link msdn.microsoft.com/en-us/library/… or #1281676 – Colenecoleopteran

You should be comparing PR.Status to IPStatus.Success. String comparison is not the correct tool in this case. – Myriapod

After you perform your ping, what are the values of some of the PingReply properties, (like PR.Address, PR.RoundtripTime, PR.reply.Buffer.Length, and PR.Options.Ttl)? Also are you sure you have the correct IP address in your code, and not a test IP address? – Goodrich

Jon Senchyna : I don't set them and yes I'm sure my IP is correct . – Hesler

In my case, if the "enable the visual studio hosting process" (location is ==>>project-> property->debug)disabled, the ping method may not work. please try! – Argolis

Answer 1

using System.Net.NetworkInformation;    

public static bool PingHost(string nameOrAddress)
{
    bool pingable = false;
    Ping pinger = null;

    try
    {
        pinger = new Ping();
        PingReply reply = pinger.Send(nameOrAddress);
        pingable = reply.Status == IPStatus.Success;
    }
    catch (PingException)
    {
        // Discard PingExceptions and return false;
    }
    finally
    {
        if (pinger != null)
        {
            pinger.Dispose();
        }
    }

    return pingable;
}

Scolopendrid

This is a code only answer. I guess it implements a correct comparison and shows how to handle possible exceptions. Could you indicate why this is the correct code compared with the code in the question? – Farnham

Don't know how many people have used this answer by copy and paste :/ Do at least a using (var pinger = new Ping()) { .. } and are early returns so evil? – Riven

There's no point in wrapping the Ping instance with a using if try/catch/finally is employed properly. It's one or the other not both. See #279402. – Scolopendrid

@Scolopendrid While that may be true, it's cleaner to use using instead, and is preferred in this case. – Detrition

I personally agree with using a using statement but you still have to catch any exceptions. – Leonorleonora

two up-votes for showing a try-catch block and declaring variables outside of the 'try' block so the immediate window can see them if you breakpoint the 'catch', but one down vote for not actually handling the exception. – Diagnosis

I suggest to add a usage example like Console.WriteLine(PingHost(host) ? $"'{host}' exists" : "no response from '{host}'"); - where host is a string containing the hostname. – Burgher

Answer 2

Using ping in C# is achieved by using the method Ping.Send(System.Net.IPAddress), which runs a ping request to the provided (valid) IP address or URL and gets a response which is called an Internet Control Message Protocol (ICMP) Packet. The packet contains a header of 20 bytes which contains the response data from the server which received the ping request. The .Net framework System.Net.NetworkInformation namespace contains a class called PingReply that has properties designed to translate the ICMP response and deliver useful information about the pinged server such as:

• IPStatus: Gets the address of the host that sends the Internet Control Message Protocol (ICMP) echo reply.
• IPAddress: Gets the number of milliseconds taken to send an Internet Control Message Protocol (ICMP) echo request and receive the corresponding ICMP echo reply message.
• RoundtripTime (System.Int64): Gets the options used to transmit the reply to an Internet Control Message Protocol (ICMP) echo request.
• PingOptions (System.Byte[]): Gets the buffer of data received in an Internet Control Message Protocol (ICMP) echo reply message.

The following is a simple example using WinForms to demonstrate how ping works in c#. By providing a valid IP address in textBox1 and clicking button1, we are creating an instance of the Ping class, a local variable PingReply, and a string to store the IP or URL address. We assign PingReply to the ping Send method, then we inspect if the request was successful by comparing the status of the reply to the property IPAddress.Success status. Finally, we extract from PingReply the information we need to display for the user, which is described above.

    using System;
    using System.Net.NetworkInformation;
    using System.Windows.Forms;

    namespace PingTest1
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }

            private void button1_Click(object sender, EventArgs e)
            {
                Ping p = new Ping();
                PingReply r;
                string s;
                s = textBox1.Text;
                r = p.Send(s);

                if (r.Status == IPStatus.Success)
                {
                    lblResult.Text = "Ping to " + s.ToString() + "[" + r.Address.ToString() + "]" + " Successful"
                       + " Response delay = " + r.RoundtripTime.ToString() + " ms" + "\n";
                }
            }

            private void textBox1_Validated(object sender, EventArgs e)
            {
                if (string.IsNullOrWhiteSpace(textBox1.Text) || textBox1.Text == "")
                {
                    MessageBox.Show("Please use valid IP or web address!!");
                }
            }
        }
    }

Willwilla

Kudos for including the using reference! – Cascabel

Can't you just write a few lines and explain your code? Couse this is not useful for people who want to understand this piece of code... – Syllogize

Sure thing @Hille, I wrote this answer quickly a couple of years ago, I will edit and add appropriate description of the answer. – Willwilla

Ping should be disposed after use using (Ping p = new Ping()) { ... } – Sublunary

Answer 3

Here is the async and more compact version using the Ping.SendPingAsync() method:

using System.Net.NetworkInformation;
using System.Threading.Tasks;

public static async Task<bool> SendPing(string hostNameOrAddress)
{
    using (var ping = new Ping())
    {
        try
        {
            PingReply result = await ping.SendPingAsync(hostNameOrAddress);
            return result.Status == IPStatus.Success;
        }
        catch
        {
            return false;
        }
    }
}

Sample usage:

bool result1 = await SendPing("127.0.0.1"); // true
bool result2 = await SendPing("non-existent-host"); // false

Catechist

Answer 4

private async void Ping_Click(object sender, RoutedEventArgs e)
{
    Ping pingSender = new Ping();
    string host = @"stackoverflow.com";
    await Task.Run(() =>{
         PingReply reply = pingSender.Send(host);
         if (reply.Status == IPStatus.Success)
         {
            Console.WriteLine("Address: {0}", reply.Address.ToString());
            Console.WriteLine("RoundTrip time: {0}", reply.RoundtripTime);
            Console.WriteLine("Time to live: {0}", reply.Options.Ttl);
            Console.WriteLine("Don't fragment: {0}", reply.Options.DontFragment);
            Console.WriteLine("Buffer size: {0}", reply.Buffer.Length);
         }
         else
         {
            Console.WriteLine("Address: {0}", reply.Status);
         }
   });           
}

Davila

Answer 5

Imports System.Net.NetworkInformation


Public Function PingHost(ByVal nameOrAddress As String) As Boolean
    Dim pingable As Boolean = False
    Dim pinger As Ping
    Dim lPingReply As PingReply

    Try
        pinger = New Ping()
        lPingReply = pinger.Send(nameOrAddress)
        MessageBox.Show(lPingReply.Status)
        If lPingReply.Status = IPStatus.Success Then

            pingable = True
        Else
            pingable = False
        End If


    Catch PingException As Exception
        pingable = False
    End Try
    Return pingable
End Function

Bathyscaphe

This code is in visual basic and the question was for C#. – Muddlehead

Answer 6

This solution implements a much less flexible method for pinging a source - not recommended in the modern paradigm of C#. At one time, IIRC, there was not a Ping(...) method.

private void button26_Click(object sender, EventArgs e)
{
    System.Diagnostics.ProcessStartInfo proc = new System.Diagnostics.ProcessStartInfo();
    proc.FileName = @"C:\windows\system32\cmd.exe";
    proc.Arguments = "/c ping -t " + tx1.Text + " ";
    System.Diagnostics.Process.Start(proc);
    tx1.Focus();
}

private void button27_Click(object sender, EventArgs e)
{
    System.Diagnostics.ProcessStartInfo proc = new System.Diagnostics.ProcessStartInfo();
    proc.FileName = @"C:\windows\system32\cmd.exe";
    proc.Arguments = "/c ping  " + tx2.Text + " ";
    System.Diagnostics.Process.Start(proc);
    tx2.Focus();
}

Wallacewallach

Can't you just write a few lines and explain your code? Couse this is not useful for people who want to understand this piece of code... – Syllogize

The code originally presented is not DRY at all. – Roughshod