Your network contains an Active Directory forest. The forest contains two domains named contoso.com and
fabrikam.com. All of the DNS servers in both of the domains run Windows Server 2012 R2.
The network contains two servers named Server1 and Server2. Server1 hosts an Active Directory- integrated
zone for contoso.com. Server2 hosts an Active Directory-integrated zone for fabrikam.com. Server1 and
Server2 connect to each other by using a WAN link.
Client computers that connect to Server1 for name resolution cannot resolve names in fabnkam.com.
You need to configure Server1 to support the resolution of names in fabnkam.com. The solution must ensure
that users in contoso.com can resolve names in fabrikam.com if the WAN link fails.
What should you do on Server1?
A.
Create a stub zone.
B.
Add a forwarder.
C.
Create a secondary zone.
D.
Create a conditional forwarder.
Explanation:
http://technet.microsoft.com/en-us/library/cc771898.aspx
When a zone that this DNS server hosts is a secondary zone, this DNS server is a secondary source for
information about this zone. The zone at this server must be obtained from another remote DNS server
computer that also hosts the zone.
With secondary, you have ability to resolve records from the other domain even if its DNS servers are
temporarily unavailable.
While secondary zones contain copies of all the resource records in the corresponding zone on the master
name server, stub zones contain only three kinds of resource records:
A copy of the SOA record for the zone.
Copies of NS records for all name servers authoritative for the zone.
Copies of A records for all name servers authoritative for the zone.http://www.windowsnetworking.com/articles-tutorials/windows-2003/DNS_Stub_Zones.html
http://technet.microsoft.com/en-us/library/cc771898.aspx
http://redmondmag.com/Articles/2004/01/01/The-Long-and-Short-of-Stub-Zones.aspx?Page=2