PingClass

A simple class to ping a computer over a network. [archival]

This is an old project of mine, that I created back in 2002.
Imported into GitHub for archival puposes only.
There will be no updates.

Introduction

This is an old class of mine. I created this class when I was developing a server monitoring system back in 2002, and I reasoned that the easiest way to know if the server was up is to ping it.

So, I started searching the web and I found a code developed for C# and after a few bumps I converted to VB .NET and the code works fine, up to the point of performance.

I use the Socket class to create a packet of raw data to be sent to the host. The send part works fine, but the response (when I listen for the echo of the packet I just sent) takes ages to process. I've checked the docs on Microsoft about the ReceiveFrom method to see if they have some insight about what's going on, and finally found a solution.

Since then I have published this code in some other places, always with good feedback from my fellow developers friends.

When I decided to publish it on my website I knew I needed to take another look at this class because so much time has passed.

One of the things that always bothered me with this class is that it was synchronous, i.e. when you call the method to ping the host it doesn't return until the host responds or a time-out is reached.

Hence I decided to go through it once more and make a second version of it with asynchronous methods too. This way is up to you to use the method that suits best your application.

Note:

In the .NET Framework 2.0 there is a namespace called NetworkInformation where a new class called Ping that supersedes this class.

PingClass Members

Public Enumerators

pingErrorCodes
Enumerates the possible errors that might occur when pinging a remote host.

Public Enum pingErrorCodes As Integer
    Success               = 0
    Unknown               = (-1)
    HostNotFound          = &H8001
    SocketDidntSend       = &H8002
    HostNotResponding     = &H8003
    TimeOut               = &H8004
    BufferTooSmall        = &H8101
    DestinationUnreahable = &H8102
    HostNotReachable      = &H8103
    ProtocolNotReachable  = &H8104
    PortNotReachable      = &H8105
    NoResourcesAvailable  = &H8106
    BadOption             = &H8107
    HardwareError         = &H8108
    PacketTooBig          = &H8109
    ReqestedTimedOut      = &H810A
    BadRequest            = &H810B
    BadRoute              = &H810C
    TTLExprdInTransit     = &H810D
    TTLExprdReassemb      = &H810E
    ParameterProblem      = &H810F
    SourceQuench          = &H8110
    OptionTooBig          = &H8111
    BadDestination        = &H8112
    AddressDeleted        = &H8113
    SpecMTUChange         = &H8114
    MTUChange             = &H8115
    Unload                = &H8116
    GeneralFailure        = &H8117
End Enum

Public Constructors

PingClass Constructor
Initializes a new instance of the PingClass Class.

Public Sub New()

Public Properties

	`DataSize` Gets or sets the size of the package to be send on the ping request. Default 32 bytes. Public Property DataSize() As Byte
	`LastError` ReadOnly The last error occurred when pinging a host. Public ReadOnly Property LastError() _ As pingErrorCodes
	`LocalHost` ReadOnly A System.Net.IPHostEntry that represents the local computer. Public ReadOnly Property LocalHost() _ As System.Net.IPHostEntry
	`RemoteHost` A System.Net.IPHostEntry that represents the remote host to be pinged. Public Property RemoteHost() _ As System.Net.IPHostEntry
	`TimeOut` The amount of time in milliseconds in which the remote host must reply. Public Property TimeOut() As Long

Public Methods

	`BeginPing` Begins the asynchronous execution of a PING request to a specified host. Public Overloads Shared Function BeginPing( _ ByVal fqdnHostName As String, _ ByVal requestCallback As PingCallback, _ ByVal stateObject As Object) _ As PingAsyncResult Public Overloads Shared Function BeginPing( _ ByVal ipAddress As System.Net.IPAddress, _ ByVal requestCallback As PingCallback, _ ByVal stateObject As Object) _ As PingAsyncResult
	`EndPing` Ends an asynchronous PING request. Public Shared Sub EndPing( _ ByVal par As PingAsyncResult)
	`Ping` Pings the remote host and return the number of milliseconds that the host took to reply. Public Overloads Function Ping() As Long Public Overloads _ Shared Function Ping( _ ByVal fqdnHostName As String) As Long Public Overloads _ Shared Function Ping( _ ByVal ipAddress As System.Net.IPAddress) As Long
	`SetRemoteHost` Sets the RemoteHost Property. Public Overloads Sub SetRemoteHost( _ ByVal fqdnHostName As String) Public Overloads Sub SetRemoteHost( _ ByVal ipAddress As System.Net.IPAddress)

Using the code

For a quick and dirty sample just take a look at the follow snippet.

MsgBox("yahoo.com took " & _
                  PingClass.Ping("yahoo.com") & _
                                     " milliseconds to reply")

Yes, it is that easy.

Background information

Always a good source of information about the Internet is the "Request For Comments". More specifically about ping and ping request are:

RFC 792: Internet Control Message Protocol.
RFC 1122: Requirements for Internet Hosts -- Communication Layers.
RFC 1812: Requirements for IP Version 4 Routers.

PaulStSmith / PingClass