NetResults Tracker Knowledge Base Article
Cannot find server or DNS error
Article ID  264
Article Type  Error Troubleshooting
Product  NetResults Tracker
Oldest Version  6.0.0
Newest Version  Latest Release
Publication Date  05/12/2006 10:06:57 AM
Last Updated  04/23/2019 11:45:57 AM
Warnings
None
Description
This article provides information for troubleshooting the error "Cannot find server or DNS error" when attempting to browse to a workgroup or the Workgroup Management System (WMS).

In general, this error can occur when a server is not responding to HTTP requests. This could be due to a network error or configuration problem. Try the following suggestions to troubleshoot this error:

  • Verify the web site where Tracker is installed is running

    For Windows 2016 / IIS 10.0
    or Windows 2012 / IIS 8.0
    or Windows 2012 R2 / IIS 8.5
    or Windows 2008 / IIS 7.0
    or Windows 2008 R2 / IIS 7.5

    1. Launch IIS Manager
    2. In the Connections pane on the left, expand the server, expand Sites and locate the web site where Tracker is installed. Right click on the site and select Manage Website. If the option "Start" is available, select it. This indicates that the web site was stopped. Try browsing to the workgroup or WMS.

    For Windows 2003 / IIS 6.0:

    1. Launch IIS Manager
    2. Right click on the web site where Tracker is installed. If the option "Start" is available, select it. This indicates that the web site was stopped. Try browsing to the workgroup or WMS.

    For Windows 2000 / IIS 5.0:

    1. Launch IIS Manager
    2. Right click on the web site where Tracker is installed. If the option "Start" is available, select it. This indicates that the web site was stopped. Try browsing to the workgroup or WMS.

  • Verify what port number is configured for the web site where Tracker is installed and ensure the URL you are using to browse to Tracker reflects this port number and check whether a host header name is configured for the web site

    For Windows 2016 / IIS 10.0
    or Windows 2012 / IIS 8.0
    or Windows 2012 R2 / IIS 8.5
    or Windows 2008 / IIS 7.0
    or Windows 2008 R2 / IIS 7.5

    1. Launch IIS Manager
    2. In the Connections pane on the left, expand the server, expand Sites and click on the web site where Tracker is installed
    3. In the Actions pane on the right, click on Bindings
    4. Check what port is listed for the appropriate type of site (http if you are not using SSL, https if SSL is enabled). For http, the standard port is 80 and for https the standard port is 443. If the port listed is "80" for http or "443" for https, then the URL does not need to specify the port number. If TCP port is set to something other than the standard port, the URL needs to include the port number. For example, if the TCP port is "99", then the URL you use to browse to Tracker needs to include the port as in "http://www.yourcompany:99.com/workgroup" instead of "http://www.yourcompany.com/workgroup".
    5. Check whether a host name is configured for the web site. If a host name is configured, try using this to browse to Tracker. For example, if the host name is "tracker.yourcompany.com", try browsing to Tracker with "http://tracker.yourcompany.com/workgroup".

    For Windows 2003 / IIS 6.0:

    1. Launch IIS Manager
    2. Right click on the web site where Tracker is installed and select Properties
    3. On the Web Site tab, check the TCP port listed. If this is "80", then the URL does not need to specify the port number. If TCP port is set to something other than 80, the URL needs to include the port number. For example, if the TCP port is "99", then the URL you use to browse to Tracker needs to include the port as in "http://www.yourcompany:99.com/workgroup" instead of "http://www.yourcompany.com/workgroup".
    4. Click on the Advanced button. Check whether a host header name is configured for the web site. If a host header name is configured, try using this to browse to Tracker. For example, if the host header name is "tracker.yourcompany.com", try browsing to Tracker with "http://tracker.yourcompany.com/workgroup".

    For Windows 2000 / IIS 5.0:

    1. Launch IIS Manager
    2. Right click on the web site where Tracker is installed and select Properties
    3. On the Web Site tab, check the TCP port listed. If this is "80", then the URL does not need to specify the port number. If TCP port is set to something other than 80, the URL needs to include the port number. For example, if the TCP port is "99", then the URL you use to browse to Tracker needs to include the port as in "http://www.yourcompany:99.com/workgroup" instead of "http://www.yourcompany.com/workgroup".
    4. Click on the Advanced button. Check whether a host header name is configured for the web site. If a host header name is configured, try using this to browse to Tracker. For example, if the host header name is "tracker.yourcompany.com", try browsing to Tracker with "http://tracker.yourcompany.com/workgroup".

  • Verify that the server is accessible using "ping" or "tracert"
    Launch a command window by going to Start -> Run, typing in "cmd" and clicking OK. Type in "ping hostname" where hostname is the TCP/IP host name of the machine where Tracker is installed. Click Enter to run this command. If the ping is successful, continue with the suggestions below. If the ping is not successful, check with your network administrator to see if there are any network issues that could be affecting your ability to access Tracker. There may also be a firewall or some other network configuration between your machine and the Tracker server that is keeping you from accessing Tracker.

  • Browse to a simple file
    Try browsing to the readme file for the workgroup or WMS by going to http://yourservername/workgroup/readme.htm or http://yourservername/ptadmin/readme.htm (where "yourservername" is the TCP/IP host name of the machine where you have installed Tracker and "workgroup" is the name of the workgroup you are trying to access). If you are not able to reach this file successfully, this indicates that the cause of the issue is probably something related to the network or IIS configuration rather than Tracker since the readme.htm file is a simple file (it's not attempting to run Tracker to display the file).

  • Check the event log to see if there are any warnings or events that will provide more information about why you are not able to access Tracker
    If the event log contains an error code 2268 "Could not load all ISAPI filters for site/service. Therefore startup aborted.", this indicates that there is an ISAPI filter that failed to load.

    ISAPI filters can be installed on a web site directly or, more commonly, indirectly was installed when an application was installed on the server (or possibly even applying some patch/update to an application). Tracker does not use ISAPI filters because they tend to interfere with other applications running on the same web server (since all data, not just the data for the application which installed the filter is run through the filter). However, many other web applications do use such filters. An ISAPI Filter is some software that is run by the IIS web server each time a web (HTTP) request comes in (or reply goes out). It has the option to (and often does) modify the data which is run through the filter (in this case all communication with your web site).

    When IIS tries to load an ISAPI Filter and fails, it does not start the web site which uses the filter. Though IIS will list the Default Web Site as "running", it in fact is not responding to web page requests which go to any "application" (for example, ptadmin, any workgroup, etc.) on the web site -- all of them will result in "Cannot find server" errors in Internet Explorer. However, it will respond to requests for some web pages which are directly in the web site itself (or in a virtual directory). When this occurs on Windows 2000 or Windows 2003, you can find out which ISAPI Filter was responsible by right-clicking on the web site in IIS Manager, selecting Properties..., and clicking the ISAPI Filters tab. The offending filter will have a red down arrow as its "Status" and if you select it, it will list "Not Loaded" as the Status. To fix this problem, select the ISAPI Filter which failed to load, click the Remove button, click the Apply button. This should restart IIS automatically, but you can also manually restart it to make certain the change takes effect. Repeat this for any ISAPI Filters which failed to load. Tracker does not use any ISAPI Filters so you don't have to worry about deleting one that it may be using (though other applications you are running on the same web server might make use of some ISAPI Filters).

    We could look up more detailed information about the particular ISAPI Filter which did not load by viewing a copy of your event logs exported to *.txt (steps below). The detail should include the full path, a search online for that particular file will usually lead to information about what application might be installing it.

    If this does not fix the problem, please do the following:

    1. Send us the latest application and system event logs

      For Windows 2016 / IIS 10.0
      or Windows 2012 / IIS 8.0
      or Windows 2012 R2 / IIS 8.5
      or Windows 2008 / IIS 7.0
      or Windows 2008 R2 / IIS 7.5

      1. Go to Start -> Administrative Tools -> Event Viewer
      2. In the left pane, expand Windows logs and click on the Application log
      3. In the Actions pane on the right, click on Save All Events As, browse to the location where you wish to save the file, enter a File name and for "Save as type", select "Text (tab delimited) (*.txt)".
      4. Repeat the above steps for the System log

      For Windows 2003 / IIS 6.0 or Windows 2000 / IIS 5.0:

      1. Go to Start -> Administrative Tools -> Event Viewer
      2. Click on the Application log in the left pane
      3. Click on Action -> Save Log File As
      4. Browse to the location where you wish to save the file, enter a File name and for "Save as type", select "Text (tab delimited) (*.txt)".
      5. Repeat the above steps for the System log

    2. Send us a screenshot of the ISAPI Filters property sheet in IIS Manager (For Windows 2000 or 2003, take the screen shot after you have tried to browse to the web site and failed).
Workaround
None