Hello,
I've searched, but have been unable to find someone address my question. We currently have 2 sites in our domain, and 2 cas/hub servers and 2 mailbox servers in a single DAG, 1 of each in each site. My questions are:
1) for the mailbox servers, we only have 1 NIC. A consultant helped deploy the servers, but now as I read more about DAG, I see they recommend 2 NICs, 1 for Replication and 1 for IMAP. Replication between DAGs has been going fine however, what are the ramifications of not having 2 NICs and where within Exchange can I address this?
2) for the DAG, there is replication going on through the VPN between each side. I understand how replication works for the most part (transaction logs and file replication/block replication), but what happens if the VPN gets cut? I assume the
transaction logs will build, and once the VPN is restored replication will resume from the primary to the secondary. However, this begs the questions:
a) since the secondary and primary are both still up but no longer communicating with each other, what happens in this scenario? Will the primary continue being the primary, and the secondary switch over to the primary
as well? The secondary won't get any emails in this case, but what happens when the VPN comes back up? Will we have to flag the former secondary as the secondary mailbox server again manually?
b) also, in regards to the transaction logs, I was told by the consultant that after a certain period of loss of connectivity between the Mailbox servers in the DAG, upon reconnect the primary will try to send all the changes that were done at once or something to that effect, instead of sending the logs in order. Is this true? What are the parameters of this? Since we're doing this over a VPN, we're concerned that in the case of a loss of connectivity for a period of time, the traffic will be too great for the WAN links to bear