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I have two Amazon EC2 Instances running Windows Server 2003 and IIS 6.0. Both the instances are created in the same region and have the same Security Group. I enables icmp for all ports and connection methods, and am able to successfully ping between both my instances. However, when I try to access the shared locations of one EC2 instance feom another, using:




I am unable to see the shared locations, and get an error saying:

No Network Provider accepted the given network path

I am able to trace from both EC2 instances using the tracert command.

Please let me know of a way to accessed shared locations between two EC2 instances.


P.S.: I know that this can alternatively be achieved using S3, but do not wish to use it for different reasons.

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up vote 15 down vote accepted

I found the answer to my own query, and here it is:


This can be found at this Microsoft knowledgebase article which deals with the ways to enable Microsoft file sharing SMB. The below matter is of relevance:

The following ports are associated with file sharing and server message block (SMB) communications:

  • Microsoft file sharing SMB: User Datagram Protocol (UDP) ports from 135 through 139 and Transmission Control Protocol (TCP) ports from 135 through 139.
  • Direct-hosted SMB traffic without a network basic input/output system (NetBIOS): port 445 (TCP and UPD).

How to do it:

  1. Enable the above ports in the security group associated with your EC2 Instance. Once you have done this, your Security Group Permissions should look something like the image below: EC2 Security Group Permissions

  2. Enable the ports in the windows firewalls of both the instances. A detailed method to do so can be found here. Skip step 7 for Windows Server.

This solves the issue, however, a restart of the instances might be needed.

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does that enable folder sharing out to the entire world? not sure thats what I would want to do. – djangofan Mar 3 '11 at 20:57
Yes it does, but you can lock it down to an IP or subnet when you specify the IP – Brien Malone May 10 '13 at 22:37
This just saved me. :) Thanks – Unykvis Oct 14 '13 at 13:16
Aaaah, thank you very much, you just made my day :) – whitesiroi May 11 '15 at 10:04

Here's the order in which I would check things:

  1. File and printer sharing is enabled on the network adapter
  2. all crucial services are running
  3. all necessary ports are open on both firewalls
  4. Check the application and system event logs for other clues
  5. Make sure there is no TCP filtering set on the network adapter.
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Thanks Jake, but those steps are ambiguous and do not answer my question. As may be apparent from my question, I am already aware of the general direction to take. Thanks anyways. – Prashant Feb 4 '11 at 18:42

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