How To set up Internal DNS for Zero Client Configuration for Public IM Clients And Setting Up IM Manager Computer DNS Services

Article:TECH91228  |  Created: 2008-01-03  |  Updated: 2012-04-19  |  Article URL
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Technical Solution



You are attempt to setup DNS for your new IM Manager implementation.


Instant messenger clients are failing to connect or are not showing as connected in the IM Manager Administrator Interface.



To implement IM Manager in your environment two DNS sources must be utilized. The origonal DNS implementation will have new entries


Configuring your current DNS infrastructure:

For an IM Manager deployment to successfully function a minimum of two separate DNS deployments must be available within the environment. The original DNS deployment will be configured with several new Forward Lookup Zones. The instructions for setting up the Forward Lookup Zones are described within Chapter 4 of the IMM_Implementation_Guide.pdf located within the Docs folder of your IM Manager installation package. The image below gives an example of a completed configuration.

For instructions on how to create zones within DNS please see Micorosft KB article 323445.

The purpose behind adding the Forward Lookup Zones into your DNS infrastructure is to force the Instant Messenger clients to be routed to the IM Manager server instead of the external Host provider for the messaging service. Chapter 4 (Table 4-2) within the IM Manager Implementation guide provides a complete list of domains to be used as Forward Lookup Zones. Once you have configured the zones, perform testing to confirm the new entries correctly route to the IP address of the IM Manager server.

From a workstation do the following

Navigate to Start>Run. Type in CMD and open a command prompt. Within the command prompt type in: NSLOOKUP

You should receive results similar to the following. In this case the IP is the IM Manager Server.

Configuring a new DNS server for your IM Manager deployment

At this point your origonal DNS solution has been configured with all supported Instant Messenger Host Names directing the results of the lookups to the IM Manager server using the Forward Lookup Zones. Because IM Manager must perform the same DNS lookups as the clients, IM Manager must use a different DNS or all lookups would point to it's own IP and a connection loopback would occur. To prevent this from occuring, a new DNS implementation must be deployed for the use of the IM Manager server.

For instructions on how to install the DNS server service please see review Microsoft KB article 814591.

Once you have installed the DNS server service it must be configured. In most environments the Root Hints will be sufficient for external DNS lookups. If this is not the case you will need to provide a Forwarder. The Forwarder provides the DNS server the ability to request lookups from other DNS servers. In this instance the forwarder will be identical to your origonal DNS servers configuration.

Windows 2008

1. Open DNS management from the Start menu: Start|Administrative Tools|DNS.
2. Right click on DNS|<server name> and select Properties.
3. Click the Forwarders tab and click the Edit... button to display the Edit Forwarders dialog box.
4. Enter the IP address of the external DNS server.  This is one that does not have the internal DNS redirections for IM hostnames pointing to IM Manager server.  Click the OK button to close the Edit Forwarders button.  The following screenshot shows this configuration:


5. Click the OK button to close the DNS properties.
6. Right click on DNS|<server name>|Conditional Forwarders and select New Conditional Forwarder... to bring up the New Conditional Forwarder dialog box.
7. Enter the internal domain in the DNS Domain textbox.
8. Enter the IP address of the internal domain controller in the IP address text box.

Windows 2003

To determine the current configuration of your origonal DNS server's forwarder right-click on the DNS servername and choose properties. In the available tabs choose Forwarders. Duplicate all information into your new DNS implemention.



Configure IM Manager for forward internal DNS requests to internal domain controller

The server IM Manager is installed on may need access to other Domain resources. This is done by configuring forwarding for the domain names.

Windows 2008

1. Open DNS management from the Start menu: Start|Administrative Tools|DNS.
2. Right click on DNS|<server name>|Conditional Forwarders and select New Conditional Forwarder... to bring up the New Conditional Forwarder dialog box.
3. Enter the internal domain in the DNS Domain textbox.
4. Enter the IP address of the internal domain controller in the IP address text box.  The following screenshot shows an example for the internal domain imm.local:



Windows 2003

Configure IM Manager server to uses itself as DNS server

The final step is to configure the Internet Protocol (TCP/IP) on the IM Manager server to use this newly created DNS server. All other DNS entries should be removed. At this point perform a DNS lookup test using the NSLOOKUP tool on the IM Manager server. This will confirm an external site and not the IM Manager server's IP has been returned. In the example below a CMD prompt was opened and the command "NSLOOKUP" was ran. You may use any of the Forward Lookup Zones host names previously configured in your origonal DNS server as a test.

If at this point all tests return the desired results, open an IM client on a workstation computer and attempt to log in. If the attempt was successful open the IM Manager AdminUI and confirm the user shows as a "Logged in user" within the IM Manager dashboard.

Technical Information
Additonal information on configuring DNS can be found in the Implementation Guide for IM Manager.


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