Back to this one again, still unresolved after more testing. The issue is, if the databases failover to the DR exchange server for any reason, while the HQ server is still up, Outlook stops working.
2 physical sites, each with a DC and configured as separate AD sites on different subnets.
Each site has a single Exchange 2010 server with ALL roles, and configured in a DAG.
HQ contains all users and the DR site is purely passive until such time as a failure.
HQ IP Range: 192.168.61.0/24
DR IP Range: 192.168.32.0/24
exch-hq - 192.168.61.40
exch-dr - 192.168.32.40
DAG Name: company-dag
DAG IP's: 192.168.61.45 & 192.168.32.45
Primary Witness: HQ Site
Alternate Witness: DR Site
Get-MailboxDatabase -Server exch-hq | fl name, rpc*
I think there a few misconfigurations in place here, from things I have read about.
Having dedicated CAS Array servers with NLB etc is NOT possible, so we are going down the DNS route which I know can work.
1. RpcClientAccessServer setting
2. DAC Mode
3. DatabaseCopyAutoActivationPolicy - does this need to be set?
4. How do you test permissions for Witness servers to be 100% they are working?
5. AllowCrossSiteRpcClientAccess - does this need to be set?
I'm thinking I should create a cas.company.com DNS entry with a low TTL, point it at exch-hq (192.168.61.40).
Then change the RpcClientAccessServer property to cas.company.com, manually changing the IP in DNS when failover occurs
But the other commands (and any I missed) - do these needs to be set?
Have I missed anything?