Understanding Time Zones; Understanding Time Synchronization; Synchronizing Local Time Using Ntp - Brocade Communications Systems VDX6720 Hardware Reference Manual

3
Setting the date and time

Understanding time zones

You can set the time zone for a switch using the clock TimeZone command. The time zone setting
has the following characteristics:
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The following regions are supported: Africa, America, Antarctica, Asia, Atlantic, Australia, Europe,
Indian, and Pacific. One of these, along with a city name, establishes the time zone.

Understanding time synchronization

To keep the time in your network current, it is recommended that the principal switch has its time
synchronized with at least one external NTP server. The other switches in the fabric will
automatically take their time from the principal switch.
All switches in the fabric maintain the current clock server value in nonvolatile memory. By default,
this value is the local clock server <LOCL> of the principal switch. Changes to the clock server
value on the principal switch are propagated to all switches in the fabric.
When a new switch enters the fabric, the time server daemon of the principal switch sends out the
addresses of all existing clock servers and the time to the new switch.
The ntp Server command accepts multiple server addresses in IPv4 format. When multiple NTP
server addresses are passed, ntp Server sets the first obtainable address as the active NTP server.
If there are no reachable time servers, then the local switch time is the default time.

Synchronizing local time using NTP

Perform the following steps to synchronize the local time using NTP.
1. Log in to the switch using the default password, (the default password is password).
2. Enter the ntp server command:
To display the NTP server IP address, use the show ntp Status [switchid <switchid> | all] command.
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The clock TimeZone setting automatically adjusts for Daylight Savings Time.
Changing the time zone on a switch updates the local time zone setup and is reflected in local
time calculations.
By default, all switches are in the Greenwich Mean Time (GMT) time zone (0,0). If all switches
in a fabric are in one time zone, it is possible for you to keep the time zone setup at the default
setting.
System services that have already started will reflect the time zone changes only after the next
reboot.
Time zone settings persist across failover for high availability.
Time zone settings are not affected by Network Time Protocol (NTP) server synchronization.
switch:admin> ntp server "<
where IPv4 address is the IP address of the first NTP server in IPv4 format, which the switch
must be able to access. The entire operand "<IPv4 address>" is optional; by default, this value
is LOCL, which uses the local clock of the principal switch as the clock server.
switch:admin> ntp server "132.163.135.131"
IPv4 address
>"
Brocade VDX 6720/6730 Hardware Reference Manual
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