In small networks where Exchange 2010 needs to be configured with redundancy , there is manual DNS works needs to be done in order MAPI clients to connect to “mounted database” in case of database fail over.
Of course if you can purchase two more servers and dedicate resources you can set CAS Array and make the outlook users MAPI experience completely automated if anything happens to “mounted” database and “healthy” database becomes “mounted” database. We are talking about small environment there are no Load balancers and no other resources, all we have is two Exchange Server and we will make our messaging environment “redundant”
- When you introduce first CAS server ( where CAS Array has not been created) The attribute called “RpcClientAccessServer” will be set to first CAS server in the AD site.
- Each Exchange Database does contain this attribute “RpcClientAccessServer” = Server Name
- If you cannot afford to have CAS array still create the CAS array with common name and give IP address as one of your mail servers.
- This will allow you tagging common name to RpcClientAccessServer attribute and you will control this with modifying DNS (A record) entry.
- In small environment you don’t have to worry about messing with TTL when you make changes to this A records
here is what I put together to make this bit clear
If database fail over occurs , all you have to do it to change the A record in DNS and pint the exiting A record to second server IP address.
Normal Operations DNS Entry will look like this
|Outlook.smtp25.org = 10.0.0.12 (mail1)|
If database fail over occurs , the DNS will look like this
|Outlook.smtp25.org = 10.0.0.13 (mail2)|
Outlook clients are connecting to = Outlook.smtp25.org
Exchange databases pointing to =Outlook.smtp25.org
Oz Casey , Dedeal
MCITP (EMA), MCITP (SA)
MCSE 2003, M+, S+, MCDST
Security+, Project +, Server +