At this stage, you have configured two additional Edge Servers that are fully configured. Although no load balancer VIPs are in place, the Edge Servers are fully functional and able to handle Office Communications Server workloads. In this section, you validate basic functionality of your two new Edge Servers. By doing so, when you add the load balancer, you can focus your troubleshooting on the load balancer. This testing will not affect your production users.

If you are using a one-armed topology, the load balancer does not need to be in place to perform this testing. However, if you are using a two-armed load balancer topology, you need to enable routing between the perimeter networks and the private edge networks for this testing to succeed.

To perform this testing, first add a temporary hostsfile entry on your Office Communications Server test pool, pointing the fully qualified domain name (FQDN) of the internal Office Communications Server Edge Server to the IP address of the particular Edge Server you test first. Then, configure the test pool with the corresponding FQDNs for your Edge Server. For example, in our sample topology:

1. On ocsstd.contoso.com, add a hosts file entry resolving ocsedge.contoso.comto 172.24.1.41.
   
   
2. On ocsstd.contoso.com, configure ocsedge.contoso.comas the Access Edge Server, webconf.contoso.comas the Web Conferencing Edge Server, and av.contoso.comas the A/V Edge Server.
   
   
3. In a command window, run ipconfig /flushdnsto clear the Domain Name System (DNS) cache.
   
   
4. Restart all services on the Front End Server to ensure that they use the updated IP address.
   
   

Next, prepare three test workstations with the Office Communicator, Outlook, and Live Meeting clients, and perform the following:

1. Add hosts file entries on each client resolving sip.contoso.comto 128.95.1.41, webconf.contoso.comto 128.95.1.51, av.contoso.comto 128.95.1.61, and ocsedge.contoso.comto 172.24.1.41.
   
   
2. In a command window, run ipconfig /flushdnsto clear the DNS cache.
   
   
3. In Office Communicator, configure connection settings to Manual, specifying ocsstd.contoso.comas the internal server name and sip.contoso.comas the external server name.
   
   
4. In the Live Meeting Client, configure the Office Communications Server to Manual, specifying ocsstd.contoso.comas the internal server name and sip.contoso.comas the external server name.
   
   
5. Using the test clients located on a combination of the Internet and the corporate networks, log on to Office Communicator by using some test accounts homed on the Standard Edition server and verify all peer-to-peer (P2P) and conference modalities work. This includes instant messaging (IM), voice, video, and desktop sharing.
   
   
6. Using one of the test clients, use the same test clients to schedule a Live Meeting conference by using Outlook. Join the meeting and verify that all Live Meeting conference modalities work.
   
   

At this stage, you have validated the functionality of the first newly added Edge Server. Now repeat the process of updating the host file entries on the Standard Edition server and the test clients, using the corresponding IP addresses for the second Edge Server. Perform the testing on Office Communicator and Live Meeting again to validate the second Edge Server.

This provides confidence that when you add a load balancer into the topology, any unexpected behavior is most likely a result of the load balancer and not the Front End Servers. The final step is to remove the test settings that you configured as follows:

1. On ocsstd.contoso.com, remove the hosts file entry that resolved to ocsedge.contoso.com.
   
   
2. In a command window, run ipconfig /flushdnsto clear the DNS cache.
   
   
3. Restart all services on the Front End Server to ensure they use the updated IP address.
   
   
4. On the test clients, remove the hosts file entry that resolved to sip.contoso.com, webconf.contoso.com, and av.contoso.com.
   
   
5. In a command window, run ipconfig /flushdnsto clear the DNS cache.
   
   
6. Restart the test clients to ensure they do not use any cached DNS entries.