Iv. creating a Windows NLB Cluster
The Client Access server is one of the biggest changes in Exchange2013, Exchange2013 CAS provides authentication, limited redirection and proxy services, and provides all the common client access protocols: HTTP, POP, and IMAP and SMTP. CAS is a stateless, thin server that does not perform any data rendering. Exchange2013 never queues or stores any content on the CAs.
Client connections have also changed as a result of Exchange2013 changes to these architectures.
1. RPC is no longer a supported direct access protocol, which means that all Outlook connections must be made using RPC over HTTPS (outlookanywhere). This may seem like a limitation, actually an improvement, most notably the need to have RPC Client access services on the Client Access server. The number of namespaces required for a site recovery solution is also two fewer than Exchange 2010, and RPC Client Access service dependencies are no longer required.
2, the Outlook client is no longer connected to the fully qualified domain name (FQDN) of the server (previously done in all versions of Exchange). With the Autodiscover feature, Outlook finds a new connection point that consists of the user's mailbox GUID + @ + domain portion of the user's primary SMTP address. With this change, the user Outlook will no longer see "the administrator has changed your mailbox." Please reboot. "This unwelcome news.
The Exchange 2013 Client Access server still uses load balancing technology for balancing to achieve high availability. and Exchange2013 supports 4-tier load balancing technology with lower cost and simpler configuration.
In Exchange 2010, CAS load Balancing first creates a CAS Array, populates the mailbox database Rpcclientaccessserver property values, and serves as a connection to the client during the automatic discovery process. CAS array does not provide any load balancing or high-availability features.
The client in Exchange 2013 now points to a unique GUID for the user's mailbox. The CAS server looks for this GUID based on the Active Directory site and then finds the correct mailbox server destination. Therefore, you no longer need to use the CAS array object.
Note:
Each Active Directory site that contains a mailbox server must contain a client Access server;
Exchange 2013 only supports Outlook 2007 and later versions;
Changes in CAS role of Exchange2013, reference
Http://blogs.technet.com/b/exchange/archive/2013/01/25/exchange-2013-client-access-server-role.aspx
Next, let's see how to configure CAS load balancing high availability
1. Install Network Load Balancing
On the CAS01 server, open Server Manager, select Add roles and features, open the Add Roles and Features wizard, check Network Load Balancing, click Next when prompted, and click "Close" until the installation is complete.
Repeat the steps above to install Network Load Balancing in CAS02