Solved

How do you determine where a port is being blocked?

Posted on 2011-03-17
5
429 Views
Last Modified: 2012-05-11
Due to last weeks earthquake in Japan our IPL's are down.  We are trying to establish alternate connections using P2P vpn tunnels through the internet.  We have the tunnel up and everything is working except email.  Both sites are part of the same AD.  The server on that side is now passing email to teh server on this side.  However our server can not connect to thier server.  We checked and Port 25 is being blocked some where in the Tunnel.  But we can not find it.  We have examined every device that we are aware of and can not find the port blocking.  

Is there a tool that we can use that would help us identify where the port is blocked?

Is there a way to make Exchange 2007 use another port for Server to Server Communication?
0
Comment
Question by:abrannon
5 Comments
 
LVL 5

Expert Comment

by:shubhanshu_jaiswal
ID: 35155853
just disable the esmtp inspection in the firewall...
0
 
LVL 2

Author Comment

by:abrannon
ID: 35155954
There are no Firewalls configured on this tunnel.
0
 
LVL 35

Expert Comment

by:Ernie Beek
ID: 35156026
Ok, how is the VPN set up then?
0
 
LVL 4

Accepted Solution

by:
cavp76 earned 500 total points
ID: 35156152
VPN traffic is encapsulated between two points, so there's no possible way to have a firewall "in the middle" of a VPN, only at each end... check that their server is not filtering connections from your server, or in any case add an entry in the IP allow list rule to allow SMTP traffic from your Exchange IP address:
To configure an IP Allow List using the Exchange Management Console, do the following:
1. Launch the Exchange Management Console.
2. Select Edge Transport in the console tree.
3. Double-click the IP Allow List item in the action pane.
4. In the IP Allow List Properties window, select the Allowed Addresses tab.
5. Click the Add button or the down arrow and choose the IP address option to add a IP address or range .
6. Click OK to add the IP address or address range.
7. The IP addresses or address ranges are shown in the IP Address(es) section of the Allowed Addresses tab in the IP Allow List Properties window.
8. Click Apply to save changes or click OK to save changes and close the window.

Hope this helps
0
 
LVL 2

Author Closing Comment

by:abrannon
ID: 35189404
This solution was on the right track.  We engaged Microsoft who also went along this path, But we never resolved teh issue.  The IPL was repaired before we resolved the problem on the temp line.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Today, still in the boom of Apple, PC's and products, nearly 50% of the computer users use Windows as graphical operating systems. If you are among those users who love windows, but are grappling to keep the system's hard drive optimized, then you s…
Examines three attack vectors, specifically, the different types of malware used in malicious attacks, web application attacks, and finally, network based attacks.  Concludes by examining the means of securing and protecting critical systems and inf…
Familiarize people with the process of utilizing SQL Server stored procedures from within Microsoft Access. Microsoft Access is a very powerful client/server development tool. One of the SQL Server objects that you can interact with from within Micr…
Familiarize people with the process of utilizing SQL Server functions from within Microsoft Access. Microsoft Access is a very powerful client/server development tool. One of the SQL Server objects that you can interact with from within Microsoft Ac…

791 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question