Hi,

Anyway to Drain the new connection from Exchange 2013 CAS.

Regards,

CAS in Exchange 2013 is basically a "smart" proxy. It does not "hold" on to any connections, it is stateless. It proxies the connection to the users mailbox based on the mailbox database it resides on.

Not exactly sure what you are trying to accomplish here.

Will.

Hi Will,

Understood that.  I think my issue is CAS & MBX are together. I want to achieved 0 outlook disconnection during server maintenance.  There is few seconds outlook client disconnected when DAG failover from 1 node to another node.

Since you have multiple CAS and they're colocated with MBX, I assume you have hardware load balancer. In such scenario Outlook is connected to HLB instead of CAS. HLB is ablr to drain the Outlook connections.

Put the server in maintenance mode by using StartDagServerMaintenance.ps1 script 

Hi Kelvin, 

Thank you for your question. 

By my understanding, Exchange 2013 is all-in-one (Mailbox role and CAS role is on the same server (if I misunderstanding, please be free to let me know).

If that, when outlook update with CAS server, it will find the original CAS has been down, then it will connect to another CAS server by SCP in AD. It will spend a few time to complete it. You could not be worry about it.  So we could refer to Vishwanaths solution let Mailbox in maintain mode. We could refer to the following link:

https://technet.microsoft.com/en-us/library/dd298065(v=exchg.150).aspx 

If there are any questions regarding this issue, please be free to let me know. 

Best Regard, 

Jim

Hi Will,

I thin Exchange 2013 CAS is not really "stateless".  Found out that there are some connections when execute

Get-Counter \MSExchange RpcClientAccess\user count ComputerName EX01, EX02.

Regards,

Kelvin

Hi Kelvin,

The Client Access server provides authentication, proxy, and limited redirection services, and offers all the usual client access protocols: HTTP, POP, IMAP, and SMTP. The Client Access server is a thin and stateless server that doesnt do any data rendering. Theres never anything queued or stored on the Client Access server.

We could refer to the following link:

https://technet.microsoft.com/en-us/library/dd298114(v=exchg.150).aspx

If there are any questions regarding this issue, please be free to let me know.

Best Regard,