Hello. I Have two Exchange 2013 CU3 Standard servers in a DAG. The servers are running Server 2012 Standard.
We’ve had a few users report that they sometimes encounter an error when trying to attach an Outlook item (e-mail message) to an existing item in a public folder calendar. The users can attach the item, but when they click on Save, a message stating that “Changes made to the item were lost due to a reconnect with the server.” appears. The clients are all running Outlook 2010 SP2.
I have determined that in at least one case, and probably a few more, this happened during or shortly after, I was rebooting our passive DAG member as part of the process of installing Microsoft updates on it. I use round robin DNS to achieve the load balancing needed to provide high availability. A check on the connectivity status of an Outlook client shows the name of the DNS record associated with this as the proxy server. The name is essentially “serverLB”. Since I have DNS records for serverLB that point to the IP address of each DAG members, is it possible that some clients are connecting to the passive node, and, therefore, affected by it being rebooted? I’d like to understand how rebooting the passive server causes the problem encountered by the Outlook users. If you have any insights into that, please share them with me. Thanks.