Staging the NLB cluster Static port change of Exchange 2010 CAS or do it all in one day ?

Question

Folks,
Here is the server deployment in my AD domain:
Email flow and Outlook client connection go through the NLB cluster VIP email.domain.com.au which is served by the following server:
PRODHT-CAS01 (HT-CAS Server Windows NLB node 1)
PRODHT-CAS02 (HT-CAS Server Windows NLB node 2)
Public Folder access through Outlook client goes through the following servers:
PRODMBX01 (Stand-alone Mailbox Server 1) no DAG
PRODMBX02 (Stand-alone Mailbox Server 2) no DAG
Can I make the changes first on the first stack of Exchange Server set as below first:
PRODHT-CAS01 (HT-CAS Server NLB node 1)
PRODMBX01 (Stand-alone Mailbox Server 1) no DAG
in order to test the Outlook email & Public Folder connectivity in the first week and then followed by the rest of the server set:
PRODHT-CAS02 (HT-CAS Server NLB node 2)
PRODMBX02 (Stand-alone Mailbox Server 2) no DAG
would that cause the NLB or user email access problem?
Do I have to make the changes all in one day for those four servers followed by the reboot?
Reason of changing: The hardware load balancer (Riverbed) requires to have static RPC port to work properly.
This is the article to change the Static port in my NLB cluster Exchange HT-CAS server role on Exchange Server 2010 SP2: http://social.technet.microsoft.com/wiki/contents/articles/864.configure-static-rpc-ports-on-an-exchange-2010-client-access-server.aspx
Thanks in advance.
/* Server Support Specialist */

Answer 1

All the servers behind the load balancer must be the same.
You can change the stand alone MBX server's RCA port as that traffic is not load balanced.
Changing Exchange is straight forward, just be careful to enter the registry keys correctly and then check AB and RCA is listening on the new static ports after you restart the services.
Cheers,
Rhoderick
Microsoft Senior Exchange PFE
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Rhoderick,
Many thanks for the suggestion. My goal here is to minimize any impact / email service downtime to the user while configuring the static ports.
1. Do I have to dissolve the Windows NLB cluster after the static port configuration on both HT-CAS servers or can I still keep the NLB cluster?
2. "All the servers behind the load balancer must be the same." Do you mean do I have to do the static RPC port the same day for all server set ?
/* Server Support Specialist */