How to forbid users from using Telnet service to connect port 25 on Exchange server?

Toate mesajele

• 4 august 2011 12:10

   

   
  

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  Hi

  You mean from the internal network that users are trying to reach the Exchange server?

  Are you using segmented networks?

  Are the servers and clients on the same subnet?

   

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  Jonas Andersson | Microsoft Community Contributor Award 2011 | MCITP: EMA 2007/2010 | Blog: http://www.testlabs.se/blog | Follow me on twitter: jonand82
  • Mesaj
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• 4 august 2011 22:11

   

   
  

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  You could use the built in windows firewall to do this.
  Dont block port 25 from IP that need to communicate with your servers, such as incoming mail from Internet.

  You could also configure the receive connector to make client connections fail. This will not strictly block the traffic only block users from submitting mail over port 25.

   

  ---

  lasse at humandata dot se, http://anewmessagehasarrived.blogspot.com
  • Mesaj
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• 5 august 2011 05:58

   

   
  

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  Hi,

  yep, both servers and clients in the same subnet. I just wanna forbid internal users from using port 25 to telent exchange server.

  Thanks.

  • Mesaj
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• 5 august 2011 07:57

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  Hi A.W,

  Easy way is that you can create a Group Policy to disable running Telnet.exe on the client computer...

  Frank Wang

  Forum Support

  Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact

  • Marcat ca răspuns de Frank.WangModerator 11 august 2011 01:35
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  • Mesaj
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• 5 august 2011 21:43

   

   
  

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  1. Also, if you have AV deployed on your client machines, they normally block this to prevent mass mail in case of a clinet infected with a virus.  If you have AV deployed on the clients, may  consider setting this up.

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  Sukh

  • Marcat ca răspuns de Frank.WangModerator 11 august 2011 01:35
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  • Mesaj
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• 8 august 2011 02:36

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  Hi A.W,

  Any updates?

  • Mesaj
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• 23 august 2011 12:38

   

   
  

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  Hi all,

  no updates, thankts for helping.

   

  • Mesaj
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• 30 ianuarie 2012 00:59

   

   
  

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  Frank,

   You stated that the

  "Easy way is that you can create a Group Policy to disable running Telnet.exe on the client computer..."

  My question is how? What are the steps and GPO path to make it work in an environment with Windows XP/Vista and Windows 2003 and Windows 2008 R2? How do you use GPO to disable telnet.exe from running on all these machines?

  Thanks,

  Tee

   

  • Mesaj
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• 8 februarie 2012 20:54

   

   
  

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  Hi all,

  Can I forbid users from using telnet service to connect port 25 on the exchange server?

  I understand I won't be able to test smtp via port 25, but I don't want someone else using it against me either.

  Thanks.

  
  Why not just allow the IPs needed and include your computer's IP to the list?  Deny your internal network.
  • Mesaj
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