HOTSPOT
Your company has a main office and a disaster recovery site. An Active Directory site named
MainSite exists for the main office. An Active Directory site named DRSite exists for the disaster
recovery site. The two sites connect to each other by using a WAN link. All users work in the main
office.
You have an Exchange Server 2013 organization. The organization contains six servers. The servers
are configured as shown in the following table.
All of the Mailbox servers are members of a database availability group (DAG) named DAG1.
After a WAN link failure, you discover that all of the active mailbox database copies are located on
MBX3, even though MBX1 and MBX2 are still running.
You need to prevent an automatic failover of DAG1 if the WAN link between the two sites fails but
the servers in both sites are still running.
The solution must prevent two active copies of the same database.
What should you do? (To answer, select the appropriate options in the answer area.)
Answer: 
Explanation:
Note:
Set-DatabaseAvailabilityGroup
The Set-DatabaseAvailabilityGroup cmdlet enables you to manage DAG properties that can’t be
managed from the Exchange Administration Center (EAC), such as configuring network discovery,
selecting the TCP port used for replication, and enabling datacenter activation coordination (DAC)
mode.
Parameters include:
/ DatacenterActivationMode
The DatacenterActivationMode parameter specifies whether datacenter activation mode is disabled
(Off) or enabled for the DAG (DagOnly).
/ WitnessServer
The WitnessServer parameter specifies the name of a server that will act as a witness for the DAG.
The server specified can’t be a member of the DAG.
/ AlternateWitnessServer
The AlternateWitnessServer parameter specifies the name of an alternate server that’s used to store
file share witness data. The specified server must not be a member of the DAG that’s configured to
use it. This parameter is used only as part of a datacenter switchover process. If the DAG is extended
across multiple datacenters in a site resilience configuration, we recommend preconfiguring the
alternate witness server and directory.