Microsoft KB Archive/290051

= HOW TO: Determine If SSL Connectivity Is Not Working on the Web Server or on an Intermediate Device =

Article ID: 290051

Article Last Modified on 11/21/2006

-

APPLIES TO


 * Microsoft Internet Information Server 3.0
 * Microsoft Internet Information Server 4.0
 * Microsoft Internet Information Services 5.0
 * Microsoft Internet Information Services 5.1

-



This article was previously published under Q290051



We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 6.0 running on Microsoft Windows Server 2003. IIS 6.0 significantly increases Web infrastructure security. For more information about IIS security-related topics, visit the following Microsoft Web site:

http://www.microsoft.com/technet/security/prodtech/IIS.mspx



IN THIS TASK
SUMMARY Determine the Cause of the Problem
 * Make an SSL Request to the Server
 * Find the Blocking Intermediate Device

Troubleshooting REFERENCES



SUMMARY
This step-by-step article describes how to determine if Secure Sockets Layer (SSL) connectivity is not working on the Web server or on a intermediate device that is on the path from the client to the Web server.

After you install a Secure Sockets Layer (SSL) certificate on a computer that is running Internet Information Server (IIS) or Internet Information Services (IIS), you may find that you cannot connect to the computer across the Internet. When you try to connect, you may receive the following error messages in the browser:

The page cannot be displayed

and

Cannot find server or DNS error

back to the top

Determine the Cause of the Problem
One possible cause of this error is that an intermediate device, such as a router or a firewall, is blocking TCP port 443 requests to the server.

back to the top

Make an SSL Request to the Server
To isolate this as a possible cause, first make sure that an SSL request to the server on the server is successful. After you install the SSL certificate, you can make an SSL request to the server by using the browser on the server (that is, connect to https://www. .com by using the browser on the Web server).

If this step is not successful, see the Troubleshooting section.

back to the top

Find the Blocking Intermediate Device
If you can connect to the server, follow these steps to confirm that an intermediate device is blocking the SSL traffic:   On the Web server, open a command prompt and use the Microsoft TCP/IP Tracert utility to connect to a known Web server on the Internet that has an SSL certificate installed (such as www.microsoft.com). This shows all of the &quot;hops&quot; between the Web server and the destination server.

The -d switch tells Tracert not to map IP addresses to host names. tracert www.microsoft.com -d 1   20 ms    10 ms    10 ms  24.25.66.1 2  <10 ms    10 ms    10 ms  24.93.65.149 3  <10 ms    10 ms   <10 ms  24.93.66.145 4  <10 ms    10 ms    10 ms  24.93.66.178 5   20 ms    20 ms    20 ms  64.240.245.81 6   20 ms    20 ms    20 ms  208.30.202.5 7   20 ms    20 ms    20 ms  144.232.8.229 8   40 ms    30 ms    30 ms  144.232.18.33 9   40 ms    30 ms    40 ms  144.232.26.1 10   40 ms    30 ms    30 ms  144.232.26.6 11   80 ms    71 ms    70 ms  144.232.18.49 12   70 ms    70 ms    70 ms  144.232.6.89   When you have obtained this information, use the Microsoft TCP/IP Telnet utility to determine which router is blocking the SSL traffic. First, try to telnet to port 443 on the first hop that is reported from the Tracert output.

For example, telnet to each hop that is listed in the Tracert output: telnet 24.93.65.149 443 When a connection is made to a listening SSL port, the telnet session shows a blank flashing cursor, as if the server is waiting for input. After several seconds, or if you press any keys, the telnet client displays the following:

Connection to host lost.

A connection to a server that is not listening on SSL immediately returns the following message:

Could not open a connection to host on port 443 : Connect failed

 Continue this process for each item on the Tracert list until you have determined the first intermediate device that is blocking SSL connections. After you find that device, work with the administrator of that device to correct this issue, and then try to connect to the site from the Internet.

back to the top

Troubleshooting
For additional information about what to do if using the browser on the Web server is not successful, click the article numbers below to view the articles in the Microsoft Knowledge Base:

260096 Page Cannot Be Displayed When You Connect through SSL

265847 Error Message: The Page Cannot Be Displayed. . . Cannot Find Server or DNS Error

324839 Cannot Open SSL-Enabled Web Site

back to the top

