how to ping from Windows Mobile application

Hello,

I can't find a way to ping in VB.net 2008 from Windows mobile application. There are no namespaces like My.Computer.Network and System.Net.NetworkInformation, from where I usually use Ping and PingCompleted handler. Is there any easy way to check if some IP is online?

Thanks!

There is a ping class in the OpenNetCF or there is some code here using IcmpSendEcho2 that you could translate to VB

Really thank you!

Hi Petevick,

I successfully P/Invoke IcmpSendEcho2 and it's working almost perfect. But there are still two things that annoyed me. Here is the IcmpSendEcho2 DllImport:

Code:

---

    <DllImport("iphlpapi.dll", SetLastError:=True)> _
    Private Shared Function IcmpSendEcho2(ByVal icmpHandle As IntPtr, _
                                          ByVal hEvent As Int32, _
                                          ByVal ApcRoutine As Int32, _
                                          ByVal ApcContext As Int32, _
                                          ByVal destinationAddress As Int32, _
                                          ByVal requestData As String, _
                                          ByVal requestSize As Int32, _
                                          ByRef requestOptions As ICMP_OPTIONS, _
                                          ByRef replyBuffer As ICMP_ECHO_REPLY, _
                                          ByVal replySize As Int32, _
                                          ByVal timeout As Int32) As Int32

---

1. When the destination host is unknown or its offline, there is still too long time out using IcmpSendEcho2. Is there a way to solve it, using hEvent.. according to this:

Code:

---

This function sends an ICMP echo request and the call returns either immediately,
if the Event parameter is non-NULL

---

In my case, I use it as Int32 which is null :confused: because I don't really know how to implement it as EventHandler

2. The time for DNS is too long if it's not in my network (it's just hang for 5-6seconds). I use this to resolve the IP address, before I start pinging:

Code:

---

                Try
                    ipEntry = Net.Dns.GetHostEntry(DestinationHost.Text)
                    destinationIP = ipEntry.AddressList(0)
                Catch ex As Exception
                End Try

---

Can you please give me a hand in this with suggestion, or just point me in the right direction?

Thank you!

If you ping from your desktop, using command prompt, to a machine you know is offline, does it take shorter, longer or the same as your code?

Well, my code is a little bit faster than cmd\ping command with the same timeout param (ping <ip> -w <timeout>). Is there a way IcmpSendEcho2 to work as it is described in MSDN: "This function sends an ICMP echo request and the call returns either immediately, if the Event parameter is non-NULL"?

Thank you Petevick!

This help?

Hello Petevick,

That was the first place from where I start after you point me, but this example is for IcmpSendEcho and work only with timeouts. This was the reason I start to P/Invoke IcmpSendEcho2 but hang on creating the event parameter (2nd one) till now... I just P/Invoke the CreateEvent from coredll.dll and this do the trick :)

Providing the code for those who are looking for this:

Code:

---

Imports HANDLE = System.IntPtr

---

Code:

---

    <DllImport("coredll.dll", SetLastError:=True, CallingConvention:=CallingConvention.Winapi, CharSet:=CharSet.Auto)> _
    Public Shared Function CreateEvent(ByVal lpEventAttributes As HANDLE, <[In](), MarshalAs(UnmanagedType.Bool)> _
                                      ByVal bManualReset As Boolean, <[In](), MarshalAs(UnmanagedType.Bool)> _
                                      ByVal bIntialState As Boolean, <[In](), MarshalAs(UnmanagedType.BStr)> _
                                      ByVal lpName As String) As HANDLE
    End Function

---

Thanks again!

The only thing that annoyed me is the DNS thingy:
The time for DNS is too long if it's not in my network. I use this to resolve the IP address, before I start pinging:

Code:

---

                Try
                    ipEntry = Net.Dns.GetHostEntry(DestinationHost.Text)
                    destinationIP = ipEntry.AddressList(0)
                Catch ex As Exception
                End Try

---

Is there a way to reduce the time for GetHostEntry?

Thanks!

Quote:

---

Originally Posted by next1

The only thing that annoyed me is the DNS thingy:
The time for DNS is too long if it's not in my network. I use this to resolve the IP address, before I start pinging:

Code:

---

                Try
                    ipEntry = Net.Dns.GetHostEntry(DestinationHost.Text)
                    destinationIP = ipEntry.AddressList(0)
                Catch ex As Exception
                End Try

---

Is there a way to reduce the time for GetHostEntry?

Thanks!

---

...or use some timeout for Net.Dns.GetHostEntry

Anyone?

Again - how long does it take if you do it from your desktop

Generally, you are not going to beat those times

I don't want to beat that times, just want the same times.

From my PC: nslookup yahoo.com answer almost immediately (less then 1sek)

From my PPC(with the code above) ~3 seconds when I try it for the first time(after program start) and ~2 seconds after the 1st time... Both (PC and PPC) are connected to same router. Any idea?

Hi,
how long does that code take on the desktop?

Guess the problem is in my PPC, because from my PC, the code above return almost immediately (less than 1 second) :cry:

Have you tried using VXUtil from www.cam.com to see what timings they get from your device - worth a shot, as you may be chasing something unattainable :)