Error System.Net.NetworkInformation.Ping

Question

So, I have a site with more than 600 devices. I am trying to ping them one by one using the standard .NET ping class. For some reason, this thread is crashing - it just stops responding after a few days. All he does is ping devices on the network. We are using Microsoft Windows Server 2008 R2. Are there any problems with the ping.NET class? I also seem to experience memory leaks, which I assume are caused by pinging. Should I just write a win32 ping dll to do the job for me, or am I doing something wrong with .NET?

private void PingDevice(out bool state, string IP) { PingReply pingReply; System.Net.NetworkInformation.Ping pingSender = null; state = false; try { pingSender = new System.Net.NetworkInformation.Ping(); pingReply = pingSender.Send(IP, 4000); state = (pingReply.Status == IPStatus.Success); // comms is on/off } catch (Exception ex) { PingGlobals.driverThread.LogIt("$E Pinging Devices:" + ex.Message + ", " + IP); } finally { if (pingSender != null) { ((IDisposable)pingSender).Dispose(); } } } 

Answer 1

When using the asynchronous version of Ping, I found that sometimes Ping never returns. I could imagine that if this happens in Async, then in Sync it just stops. The answer I found for Async is to set a timeout (longer than a Ping timeout), and then call SendAsyncCancel before sending SendAsync.

Answer 2

Creating new instances of the System.Net.NetworkInformation.Ping class seems to lead to a memory leak on the 2008 server. If you save one (or one hundred) instances and reuse them, this problem disappears. Just be very careful when accessing it from multiple threads.

Answer 3

This is the issue reported for .Net versions below 3.5
There is a Microsoft article describing the problem and its solutions here .