Why there is a "Microsoft Exchange RPC Client Access" service in CAS and MBX server ?
Public folder connections from an Outlook client occur against the RPC Client Access service on the Mailbox server role. It is optional on a Mailbox server, only required for Outlook public folder access.
How to point RPC Cas service to Newly created Database ?
Get-Mailboxdatabase | Set-Mailboxdatabase -RpcClientAccessServer "CASArrayname.domain.com"
Setting Static RPC ports for MAPI and Directory Access ?
By default you need to open the TCP 135 EndPointMapper and the Dynamic RPC range TCP 1024-65535 between your internal Client network and the CAS server or Arrays and your Mailbox servers.
On CAS servers, for Mailbox connections, add D-Word “TCP/IP Port" and set the value 55000,
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeRpc\ParametersSystem
also from
Microsoft.exchange.addressbook.service.exe.config
Open the file in Notepad and then change the “RpcTcpPort” value from the default assignment of “0” to the port you want Outlook clients and Exchange to use for the directory access via the NSPI EndPoint. In this article we use port 55001.
Unicast Mode
With the WNLB cluster configured in unicast mode, the MAC address of each server’s network adapter will be changed to a virtual cluster MAC address, which is the MAC address that will be used by all servers in the Windows NLB cluster. When unicast mode is enabled, clients can only connect to the servers via the VIP address on the network interface card (NIC) that has been configured with the cluster MAC address.
Multicast mode
With the Windows NLB cluster configured in multicast mode, a multicast MAC address is added to the cluster adapter of each server in the cluster. Note that I write “is added”, as each server will retain their original MAC address.
A Windows NLB cluster, no matter what mode it is configured in, works with just a single network adapter installed in each server, but it is recommended to install a second network adapter in each server, in order to achieve optimal performance, and to separate ordinary and cluster related network traffic.
So what mode should I use for my Exchange 2010 CAS array and how many network adapters should I install in each Client Access server? Well, a best practice recommendation is to install two network adapters and use unicast mode, so that the host and cluster network traffic are separated on their own respective network interface. However, if you only have the option of installing one NIC in each CAS server or if you’re forced to using multi-cast mode because of the switches used in your organization, you should pick multicast mode.