You are the administrator for your company’s UCM network. Examine the exhibit below, and answer the
question:

Which of the following is most likely true?

A.
The DNS server is down.

B.
The UCM server is not configured to use DNS.

C.
The UCM server’s host name is cucm862.

D.
The end user’s user name is Jabberwocky.

E.
The workstation is using a hosts file to resolve the UCM server’s name.

Explanation:
Most likely, the Cisco Unified Communications Manager (UCM) server’s host name is cucm862. Based on the
information in the browser’s location bar, you can determine that the administrator in this scenario connected to
the UCM Administration page by using the Uniform Resource Locator (URL) https:// cucm862:8443/ccmadmin.If the workstation were not able to resolve the host name cucm862 to an IP address, the administrator would
not be able to connect to the UCM Administration page.
Although UCM can be deployed with a Domain Name System (DNS) configuration, Cisco recommends that
administrators who are deploying UCM in a high availability environment not rely on DNS to connect endpoints
to UCM, because doing so could create a single point of failure. Even if DNS is required for systems
management purposes, Cisco recommends not using host names to configure endpoints, gateways, and UCM
servers.
There is not enough information in the scenario to determine whether the workstation is using a hosts file, or
whether the UCM server is configured to use DNS name resolution. Even though the Cisco Jabber client is
connecting to the UCM server by using the IP address of 192.168.51.10, the administrator’s workstation has
been able to resolve the UCM server’s host name. The workstation could have resolved the host name of
cucm862 by using either a DNS server or a local hosts file.
When Cisco Jabber cannot connect to a server by using either DNS or an IP address, the Cannot communicate
with the server message will appear on the Cisco Jabber client’s login screen. The same message will appear if
the server to which Cisco Jabber is configured to connect is down. In this scenario, the Cisco Jabber client has
successfully connected to the UCM device at 192.168.51.10.
The end user’s user name is not Jabberwocky. In this scenario, the user’s login information has not been
provided. Jabberwocky is the name of the Cisco Jabber client endpoint in UCM.
There is not enough information to determine whether a DNS server is down, because the Cisco Jabber client
is not relying on DNS to connect to the UCM server. If the Cisco Jabber user logged in with a fully qualified
domain name (FQDN), you could surmise that the DNS server is still functional because Cisco Jabber was able
to resolve the login credential. However, you do not know what credentials were used to log in.

Cisco: Network Infrastructure: Domain Name System (DNS)