TraceRoute and Ping in C#
Given that I had to write a TraceRoute class today I figured I might as well share the source code.
using System.Collections.Generic;
using System.Net.NetworkInformation;
using System.Text;
using System.Net;
namespace Answer
{
public class TraceRoute
{
private const string Data = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
public static IEnumerable<IPAddress> GetTraceRoute(string hostNameOrAddress)
{
return GetTraceRoute(hostNameOrAddress, 1);
}
private static IEnumerable<IPAddress> GetTraceRoute(string hostNameOrAddress, int ttl)
{
Ping pinger = new Ping();
PingOptions pingerOptions = new PingOptions(ttl, true);
int timeout = 10000;
byte[] buffer = Encoding.ASCII.GetBytes(Data);
PingReply reply = default(PingReply);
reply = pinger.Send(hostNameOrAddress, timeout, buffer, pingerOptions);
List<IPAddress> result = new List<IPAddress>();
if (reply.Status == IPStatus.Success)
{
result.Add(reply.Address);
}
else if (reply.Status == IPStatus.TtlExpired || reply.Status == IPStatus.TimedOut)
{
//add the currently returned address if an address was found with this TTL
if (reply.Status == IPStatus.TtlExpired) result.Add(reply.Address);
//recurse to get the next address...
IEnumerable<IPAddress> tempResult = default(IEnumerable<IPAddress>);
tempResult = GetTraceRoute(hostNameOrAddress, ttl + 1);
result.AddRange(tempResult);
}
else
{
//failure
}
return result;
}
}
}
And a VB version for anyone that wants/needs it
Public Class TraceRoute
Private Const Data As String = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
Public Shared Function GetTraceRoute(ByVal hostNameOrAddress As String) As IEnumerable(Of IPAddress)
Return GetTraceRoute(hostNameOrAddress, 1)
End Function
Private Shared Function GetTraceRoute(ByVal hostNameOrAddress As String, ByVal ttl As Integer) As IEnumerable(Of IPAddress)
Dim pinger As Ping = New Ping
Dim pingerOptions As PingOptions = New PingOptions(ttl, True)
Dim timeout As Integer = 10000
Dim buffer() As Byte = Encoding.ASCII.GetBytes(Data)
Dim reply As PingReply
reply = pinger.Send(hostNameOrAddress, timeout, buffer, pingerOptions)
Dim result As List(Of IPAddress) = New List(Of IPAddress)
If reply.Status = IPStatus.Success Then
result.Add(reply.Address)
ElseIf reply.Status = IPStatus.TtlExpired Then
'add the currently returned address
result.Add(reply.Address)
'recurse to get the next address...
Dim tempResult As IEnumerable(Of IPAddress)
tempResult = GetTraceRoute(hostNameOrAddress, ttl + 1)
result.AddRange(tempResult)
Else
'failure
End If
Return result
End Function
End Class
What follows is a significantly better C# implementation of tracert
than exists in other answers thus far.
public static IEnumerable<IPAddress> GetTraceRoute(string hostname)
{
// following are similar to the defaults in the "traceroute" unix command.
const int timeout = 10000;
const int maxTTL = 30;
const int bufferSize = 32;
byte[] buffer = new byte[bufferSize];
new Random().NextBytes(buffer);
using (var pinger = new Ping())
{
for (int ttl = 1; ttl <= maxTTL; ttl++)
{
PingOptions options = new PingOptions(ttl, true);
PingReply reply = pinger.Send(hostname, timeout, buffer, options);
// we've found a route at this ttl
if (reply.Status == IPStatus.Success || reply.Status == IPStatus.TtlExpired)
yield return reply.Address;
// if we reach a status other than expired or timed out, we're done searching or there has been an error
if (reply.Status != IPStatus.TtlExpired && reply.Status != IPStatus.TimedOut)
break;
}
}
}
Pitfalls fixed here that are present in other answers include:
- It's lazy. Ex: it properly uses enumerable / an iterator so don't have to compute the entire tree, you can stop at any point by breaking out of your own consuming loop.
maxTTL
implemented so the function doesnt spin on forever.bufferSize
option which is consistent with other tracert implementations.- It's super concise and clean. It's contained in a single method and is considerably shorter than other options here.
Although the Base Class Library includes Ping, the BCL does not include any tracert functionality.
However, a quick search reveals two open-source attempts, the first in C# the second in C++:
- http://www.codeproject.com/KB/IP/tracert.aspx
- http://www.codeguru.com/Cpp/I-N/network/basicnetworkoperations/article.php/c5457/