C# Telnet Library

Question

Is there a good, free telnet library available for C# (not ASP .NET)? I have found a few on google, but they all have one issue or another (don't support login/password, don't support a scripted mode).

I am assuming that MS still has not included a telnet library as part of .NET v3.5 as I couldn't find it if it was. I would loooooove to be wrong though.

Answer 1

I doubt very much a telnet library will ever be part of the .Net BCL, although you do have almost full socket support so it wouldnt be too hard to emulate a telnet client, Telnet in its general implementation is a legacy and dying technology that where exists generally sits behind a nice new modern facade. In terms of Unix/Linux variants you'll find that out the box its SSH and enabling telnet is generally considered poor practice.

You could check out: http://granados.sourceforge.net/ - SSH Library for .Net http://www.tamirgal.com/home/dev.aspx?Item=SharpSsh

You'll still need to put in place your own wrapper to handle events for feeding in input in a scripted manner.

Answer 2

there are several on the CodeProject

here 'i think this is the one i use, although im not sure
Search

But you can also telnet using the Net.Sockets class too:

_socket = New Socket(Net.Sockets.AddressFamily.InterNetwork, Net.Sockets.SocketType.Stream, Net.Sockets.ProtocolType.Tcp)
_socket.Connect(address, port)

Private Sub SendCommand(ByVal cmd As String)

 If Not String.IsNullOrEmpty(cmd) Then

  Dim send() As Byte = Text.Encoding.ASCII.GetBytes(cmd & vbCrLf)

  _socket.Send(send, send.Length, SocketFlags.None)

  Threading.Thread.Sleep(50) 'used as the code used for the response can fire too quickly

 End If

End Sub

EDIT: Added comments

Answer 3

I ended up finding MinimalistTelnet and adapted it to my uses. I ended up needing to be able to heavily modify the code due to the unique** device that I am attempting to attach to.

** Unique in this instance can be validly interpreted as brain-dead.

Answer 4

Hi,

I am currently evaluating two .NET (v2.0) C# Telnet libraries that may be of interest:

• http://www.thoughtproject.com/Libraries/Telnet/
• http://dotnettelnet.sourceforge.net/

Hope this helps.

Regards, Andy.

Answer 5

Best C# Telnet Lib I've found is called Minimalistic Telnet. Very easy to understand, use and modify. It works great for the Cisco routers I need to configure.

http://www.codeproject.com/KB/IP/MinimalisticTelnet.aspx

Answer 6

Here is a telnet library and program that uses it as an example. All the source (including the library source) is at the bottom of the article.

The example performs a login to a Cisco router and downloads the configuration

http://www.xpresslearn.com/networking/code/csharp-telnet-client

Answer 7

Another one with a different concept: http://www.klausbasan.de/misc/telnet/index.html