Which of the following show clock command output symbols indicates that time reported by the software clock
is authoritative but not synchronized with the configured time source? (Select the best answer.)

A.
#

B.
*

C.
~

D.
.

E.
+

Explanation:
The period (.) is the show clock command output symbol that indicates that time reported by the software clock
is authoritative but not synchronized with the configured time source. The show clock command displays the
current time as reported by the system software clock. The time can be configured manually or derived from an
external time source, such as a Network Time Protocol (NTP) server. If the software clock is configured to use
an external time source and that source becomes unreachable, the time might become unsynchronized due to
clock drift. When this happens, the show clockcommand uses the . symbol to indicate that the time is still
considered authoritative but is no longer guaranteed to be synchronized with the external time source. The
following command output indicates that the software clock is authoritative but not synchronized with its time
source:
.10:06:40.603 UTC Tue Jan 13 2015
The asterisk (*) is displayed in the output of the show clock command to indicate that time reported by the
software clock is not authoritative. If the software clock is not set by a timing source, the system will flag the
time as not authoritative and the output of the show clock command will indicate the flag with the * symbol, as
shown in the following command output:
*10:06:40.603 UTC Tue Jan 13 2015
By contrast, if the time is set by a timing source and is synchronized with that source, the time is considered
authoritative and the output of the show clock command will not display any additional symbols. For example,
the absence of additional symbols in the following command output indicates that the software clock is
authoritative and synchronized with its time source:
10:06:40.603 UTC Tue Jan 13 2015
The pound sign (#), tilde (~), and plus sign (+) are displayed in the output of the show ntp associations
command, not the show clock command. The output of the show ntp associations command shows the IP
addresses of configured NTP servers and their respective clock sources, strata, and reachability statistics. For
example, in the following command output, the NTP server at IP address 128.227.205.3 is a stratum 1 server
that uses a global positioning system (GPS) time source as its time source:
address ref clock st when poll reach delay offset disp
*~128.227.205.3 .GPS. 1 17 64 377 0.000 0.000 0.230
~71.40.128.157 204.9.54.119 2 18 64 377 0.000 321 1.816
~184.22.97.162 132.163.4.101 2 5 64 377 0.000 314 1.134
* sys.peer, # selected, + candidate, outlyer, x falseticker, ~ configured
The * next to the IP address in the command output indicates that this server is an NTP master time source to
which the Cisco device is synched. A # next to the IP address indicates that the server is an NTP master time
source to which the Cisco device is not yet synched. A + next to the IP address indicates that the server is an
NTP master time source that is selected for synchronization but the synchronization process has not yet begun.
A ~next to an IP address indicates that the address was manually configured.

Cisco: Cisco IOS Basic System Management Command Reference: show clock