Clock Management Commands

To use these commands in System Admin VM, you must be in a user group associated with appropriate command rules and data rules. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

clock timezone

To set the time zone for display, use the clock timezone command in System Admin Config mode or XR Config mode. To remove the time zone setting, use the no form of this command.

clock timezone zone region

no clock timezone

Syntax Description

zone

Name of the time zone to be displayed when standard time is in effect.

region

Sets the offset according to the region specified.

Command Default

UTC

Command Modes

System Admin Config mode

XR Config mode

Command History

Release

Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

This table lists common time zone acronyms used for the zone argument.

Table 1. Common Time Zone Acronyms

Acronym

Time Zone Name and UTC Offset

Europe

GMT

Greenwich Mean Time, as UTC.

BST

British Summer Time, as UTC plus 1 hour.

IST

Irish Summer Time, as UTC plus 1 hour.

WET

Western Europe Time, as UTC.

WEST

Western Europe Summer Time, as UTC plus 1 hour.

CET

Central Europe Time, as UTC plus 1 hour.

CEST

Central Europe Summer Time, as UTC plus 2 hours.

EET

Eastern Europe Time, as UTC plus 2 hours.

EEST

Eastern Europe Summer Time, as UTC plus 3 hours.

MSK

Moscow Time, as UTC plus 3 hours.

MSD

Moscow Summer Time, as UTC plus 4 hours.

United States and Canada

AST

Atlantic Standard Time, as UTC minus 4 hours.

ADT

Atlantic Daylight Time, as UTC minus 3 hours.

ET

Eastern Time, either as EST or EDT, depending on place and time of year.

EST

Eastern Standard Time, as UTC minus 5 hours.

EDT

Eastern Daylight Saving Time, as UTC minus 4 hours.

CT

Central Time, either as CST or CDT, depending on place and time of year.

CST

Central Standard Time, as UTC minus 6 hours.

CDT

Central Daylight Saving Time, as UTC minus 5 hours.

MT

Mountain Time, either as MST or MDT, depending on place and time of year.

MST

Mountain Standard Time, as UTC minus 7 hours.

MDT

Mountain Daylight Saving Time, as UTC minus 6 hours.

PT

Pacific Time, either as PST or PDT, depending on place and time of year.

PST

Pacific Standard Time, as UTC minus 8 hours.

PDT

Pacific Daylight Saving Time, as UTC minus 7 hours.

AKST

Alaska Standard Time, as UTC minus 9 hours.

AKDT

Alaska Standard Daylight Saving Time, as UTC minus 8 hours.

HST

Hawaiian Standard Time, as UTC minus 10 hours.

Australia

WST

Western Standard Time, as UTC plus 8 hours.

CST

Central Standard Time, as UTC plus 9.5 hours.

EST

Eastern Standard/Summer Time, as UTC plus 10 hours (plus 11 hours during summer time).

This table lists an alternative method for referring to time zones, in which single letters are used to refer to the time zone difference from UTC. Using this method, the letter Z is used to indicate the zero meridian, equivalent to UTC, and the letter J (Juliet) is used to refer to the local time zone. Using this method, the International Date Line is between time zones M and Y.

Table 2. Single-Letter Time Zone Designators

Letter Designator

Word Designator

Difference from UTC

Y

Yankee

UTC minus 12 hours.

X

Xray

UTC minus 11 hours.

W

Whiskey

UTC minus 10 hours.

V

Victor

UTC minus 9 hours.

U

Uniform

UTC minus 8 hours.

T

Tango

UTC minus 7 hours.

S

Sierra

UTC minus 6 hours.

R

Romeo

UTC minus 5 hours.

Q

Quebec

UTC minus 4 hours.

P

Papa

UTC minus 3 hours.

O

Oscar

UTC minus 2 hours.

N

November

UTC minus 1 hour.

Z

Zulu

Same as UTC.

A

Alpha

UTC plus 1 hour.

B

Bravo

UTC plus 2 hours.

C

Charlie

UTC plus 3 hours.

D

Delta

UTC plus 4 hours.

E

Echo

UTC plus 5 hours.

F

Foxtrot

UTC plus 6 hours.

G

Golf

UTC plus 7 hours.

H

Hotel

UTC plus 8 hours.

I

India

UTC plus 9 hours.

K

Kilo

UTC plus 10 hours.

L

Lima

UTC plus 11 hours.

M

Mike

UTC plus 12 hours.

Examples

This example shows how to set the time zone to IST Asia/Calcutta: 

sysadmin-vm:0_RP0# config
sysadmin-vm:0_RP0(config)# clock timezone IST Asia/Calcutta

clock read-calendar

To manually copy the hardware clock (calendar) settings into the software clock, use the clock read-calendar command in XR EXEC modeSystem Admin EXEC mode.

clock read-calendar

Syntax Description

This command has no keywords or arguments.

Command Default

Read calendar is disabled.

Command Modes

XR EXEC mode

System Admin EXEC mode

Command History

Release

Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

The calendar clock is a hardware system clock that runs continuously, even if the router is powered off or rebooted. The hardware system clock is separate from the software clock settings, which are erased when the router is power cycled or rebooted.

Use the clock read-calendar command to manually copy the hardware clock setting into the software clock.

Examples

In the following example, the hardware clock settings are copied to the software clock with the clock read-calendar command. The show clock command is then entered to display the new software clock settings. 

sysadmin-vm:0_RP0# clock read-calendar
sysadmin-vm:0_RP0# show clock
  Thu Jul  18 14:56:51.888 UTC
Thu Jul 18 14:56:52 UTC 2013

ntp authenticate

To enable Network Time Protocol (NTP) authentication, use the ntp authenticate command in the System Admin Config or XR Config mode. To restore the system to its default condition, use the no form of this command.

ntp authenticate

no ntp authenticate

Syntax Description

This command has no keywords or arguments.

Command Default

None

Command Modes

System Admin Config

XR Config

Command History

Release Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

Use the authenticate command to enable NTP authentication. When NTP authentication is enabled, the system does not synchronize to a time source unless it carries one of the authentication keys specified by the trusted-key command. NTP synchronization will not take place until valid authentication credentials are available with the source.

Examples

The following example shows how to enable ntp authentication: 

sysadmin-vm:0_RP0#config
sysadmin-vm:0_RP0(config)#ntp authenticate

ntp authentication-key

To define an authentication key for a trusted Network Time Protocol (NTP) time source, use the ntp authentication-key command in the System Admin Config and XR Config modes. To restore the system to its default condition, use the no form of this command.

ntp authentication-key key-number md5 {clear | encrypted} key-name

no ntp authentication-key key-number md5 {clear | encrypted} key-name

Syntax Description

key-number

Authentication key. A number in the range from 1 to 65535.

md5

Provides message authentication support using the Message Digest 5 (MD5) algorithm.

clear

Specifies that the key value entered after this keyword is unencrypted.

encrypted

Specifies that the key value entered after this keyword is encrypted.

key-number

Key value. The maximum length is 32 characters.

Command Default

No authentication key is defined for NTP.

Command Modes

System Admin Config

XR Config

Command History

Release Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

Use the authentication-key command to define authentication keys for use with trusted NTP time sources. Use the authentication-key command only after enabling authentication.

Examples

This example shows how to configure the system to synchronize only to systems providing authentication key 42 in their NTP packets: 

sysadmin-vm:0_RP0#config
sysadmin-vm:0_RP0(config)#ntp authentication-key 42 md5 clear key1

ntp peer

To configure the system clock to synchronize a peer or to be synchronized by a peer, use the ntp peer command in the System Admin Config mode. To remove the peer command from the configuration file and restore the system to its default condition with respect to the command, use the no form of this command.

ntp peer peer-name [ [key-id id] | [prefer] | [version number]]

no ntp peer peer-name [ [key-id id] | [prefer] | [version number]]

Syntax Description

peer-name

Name of the NTP peer.

key-id key-id

Defines the authentication key, where the key-id argument is the authentication key to use when packets are sent to this peer. The authentication key is also used for packets received from the peer. By default, no authentication key is used.

prefer

Makes this peer the preferred peer that provides synchronization.

version number

Defines the Network Time Protocol (NTP) version number, where the number argument is a value from 1 to 4. The default is 4.

Command Default

No peers are configured by default.

Command Modes

System Admin Config

Command History

Release Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

Use the ntp peer command to allow this machine to synchronize with the peer, or conversely.


Caution
Although using the prefer keyword can help reduce the switching among peers, you should avoid using the keyword because it interferes with the source selection mechanism of NTP and can result in a degradation of performance.

Note
To change the configuration of a specific IP address from peer to server or from server to peer, use the no form of the peer or server command to remove the current configuration before you perform the new configuration. If you do not remove the old configuration before performing the new configuration, the new configuration does not overwrite the old configuration.

The key-id key-id argument is effective only if authentication is enabled.

To verify if the configuration is applied, users can execute the show running-config ntp command. To verify the state of the ntp association, users can execute the show ntp associations command.

Examples

The following example shows how to configure ntp peer: 

sysadmin-vm:0_RP0#config
sysadmin-vm:0_RP0(config)#ntp peer test key-id 2

ntp server

To allow the system clock to be synchronized by a time server, use the ntp server command in the System Admin Config mode. To remove the ntp server command from the configuration file and restore the system to its default condition with respect to this command, use the no form of this command.

ntp server server-name [ [key-id id] | [prefer] | [version number]]

no ntp server server-name [ [key-id id] | [prefer] | [version number]]

Syntax Description

server-name

Name or the IP address of the NTP server.

key-id key-id

Defines the authentication key, where the key-id argument is the authentication key to use when packets are sent to this server. By default, no authentication key is used.

prefer

Makes this server the preferred server that provides synchronization.

version number

Defines the Network Time Protocol (NTP) version number, where the number argument is a value from 1 to 4. The default is 4.

Command Default

No servers are configured by default.

Command Modes

System Admin Config

Command History

Release Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

Using the prefer keyword reduces switching back and forth among servers.


Note
To change the configuration of a specific IP address from peer to server or from server to peer, use the no form of the peer or server command to remove the current configuration before you perform the new configuration. If you do not remove the old configuration before performing the new configuration, the new configuration does not overwrite the old configuration.

The key-id key-id argument is effective only if authentication is enabled.

To verify if the configuration is applied, users can execute the show running-config ntp command. To verify the state of the ntp association, users can execute the show ntp associations command.

Examples

The following example shows how to configure ntp server: 

sysadmin-vm:0_RP0#config
sysadmin-vm:0_RP0(config)#ntp server test key-id 2

ntp trusted-key

To designate a Network Time Protocol (NTP) trusted key, use the ntp trusted-key command in the System Admin Config and XR Config modes. To remove the trusted-key command from the configuration file and restore the system to its default condition with respect to this command, use the no form of this command.

ntp trusted-key key-number

no ntp trusted-key key-number

Syntax Description

key-number

Authentication key number to be trusted. Range is from 1 to 65535.

Command Default

No NTP trusted key is designated.

Command Modes

System Admin Config

XR Config

Command History

Release Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

The ntp trusted-key command is effective only if authentication is enabled.

If authentication is enabled, use the trusted-key command to define one or more key numbers (corresponding to the keys defined with the authentication-key [NTP] command) that a NTP system must provide in its NTP packets for this system to synchronize to it. Because the other system must know the correct authentication key, this precaution provides protection against accidentally synchronizing the system to a system that is not trusted.

Examples

The following example shows how to designate an ntp trusted key: 

sysadmin-vm:0_RP0#config
sysadmin-vm:0_RP0(config)#ntp authentication-key 1 md5 060506324F41 7
sysadmin-vm:0_RP0(config)#ntp trusted-key 1
sysadmin-vm:0_RP0(config)#ntp clock-period 17179865
sysadmin-vm:0_RP0(config)#ntp server 12.0.0.1 key 1

show calendar

To display the system time and date, use the show calendar command in the System Admin EXEC and XR EXEC mode.

show calendar

Syntax Description

This command has no keywords or arguments.

Command Default

None

Command Modes

System Admin EXEC

XR EXEC

Command History

Release

Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

The time format of the show calendar output depends on the time format set using the clock timezone command.

Examples

The following example shows sample output from the show calendar command: 

 
sysadmin-vm:0_RP0# show calendar
Thu Jul  18 17:32:28.640 UTC

show clock

To display the system clock, use the show clock command in the System Admin EXEC mode.

show clock [trace {timezone_config | timezone_notify} {all | trace-name} location node-id [trace-attribute] ]

Syntax Description

trace-name

Trace buffer name.

timezone_config

Displays timezone configuration traces.

timezone_notify

Displays timezone notify traces.

location node-id

Specifies the target location. The node-id argument is expressed in the rack/ slot notation.

trace-attribute

Trace attribute.

all

Displays all the details.

Command Default

None

Command Modes

System Admin EXEC

Command History

Release Modification

Release 5.0.0

This command was introduced.

Usage Guidelines

The time format of the show clock output depends on the time format set using the clock timezone command

Examples

This example shows how to view the output of the show clock command: 
 
sysadmin-vm:0_RP0#show clock
                         
Thu Aug  22 07:29:17.225 UTC
Thu Aug 22 07:29:17 UTC 2013

show ntp associations

To display the status of Network Time Protocol (NTP) associations and to view the nodes participating in the NTP synchronization, use the show ntp associations command in System Admin EXEC mode.

show ntp associations

Syntax Description

This command has no keywords or arguments.

Command Default

None

Command Modes

System Admin EXEC

Command History

Release

Modification

Release 5.0.0

This command was introduced.

Examples

This example shows the sample output of the show ntp associations command: 
sysadmin-vm:0_RP0#show ntp associations
Mon Aug  19 20:23:22.775 UTC
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
external:
 12.28.59.200    10.81.254.131    2 u   15   64    1    0.186    0.138   0.000
internal:
 192.0.4.1       127.0.0.1       12 u    4   64    1    0.171   17.240   0.000