In our case we will assume that we are using Windows load balance and not H/W load balance
Preparing the NLB Cluster for Updates:
The first thing is to remove this server from load balance and make sure there is no active session on that server
1- Issue a Drainstop command to the server (By this you are stop accepting any new session on that server)
When the server has no more active connections it will be in a stopped state
2- Set the default state of the server to Stopped. This will prevent it from automatically starting and accepting client connections after any reboots that the updates require, to allow you time to verify the updates were successful first before rejoining the NLB cluster.
Stop Conflicting Services:
Stop any service that affect and contact Exchange like (forefront – Antivirus – Anti spam – Backup Solution)
Updating the Server:
Run the setup.exe file and wait till completes
Restart the server
Verifying the Update:
1- Run the command Get-ExchangeServer to get the version of the Exchange server ( Version 14.3 refer to Exchange 2010 SP3)
2- Run the command get-service *exchange*
Returning the Server to Production:
1- Return all the third party services that communicate with Exchange to its normal status (Anti spam – Antivirus – Backup – …….)
2- Start the NLB
Set the default status of the NLB to be started
