You support a customer whose network environment includes Microsoft Lync Server 2013
Enterprise, with two Front End Servers and two Back End Servers. The Back End Servers are deployed
in a high availability configuration. You create a Front End pool named pool.contoso.com and
implement DNS load balancing for client access to the Lync servers. Your internal DNS records have
the following configuration:

Your Lync 2013 clients fail to sign in automatically. The trace log of failed sign-in attempt is as
follows:

A.
Create the following host records:
Pool A 192.168.1.10
Pool A 192.168.1.11

B.
Create the following host records:
Sip A 192.162.1.20
Sip A 192.163.1.21

C.
Create the following service record:
_sip._tls.concoso.com SRV
Priority 0, weight 0, port 5061, pooIOl.coato30.com

D.
Create the following host records:
Pool A 192.168.1.20
Pool A 192.168.1.21

E.
Create the following service record:
_sipinternal.tls.contoso.com SRV
Priority 0, weight 0, port 5061, FrontEndServer1.contoso.com