Brocade Communications Systems VDX 6940 Series, Hardware Installation Manual, Page: 70 / 136

Setting the date and time
Brocade devices maintain the current date and time inside a real-time clock (RTC) circuit. Date and
time are used for logging events. The device does not depend on the date and time for its operation;
even with an incorrect date and time value, the device functions properly. However, because the date
and time are used for logging, error detection, and troubleshooting, you should set them correctly.
Time zones
You can set the time zone for the device by using the clock timezone command. The time zone
setting has the following characteristics:
• The clock timezone setting automatically adjusts for Daylight Savings Time.
• Changing the time zone on a device updates the local time zone setup and is reflected in local time
calculations.
• By default, all devices are in the Greenwich Mean Time (GMT) time zone (0,0). If all devices 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.
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.
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 devices in the fabric will automatically
take their time from the principal switch.
All devices in the fabric maintain the current clock server value in nonvolatile memory. By default, this
value is the local clock server 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 device 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 device.
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 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 device using the admin account (the default password is password ).
2. Enter configure terminal to change to global configuration mode
device# configure terminal
Entering configuration mode terminal
3. Enter the ntp server IPv4 address command, where IPv4 address is the IP address of the first NTP
server in IPv4 format, which the device must be able to access. The IPv4 address variable is
Setting the date and time
70 Brocade VDX 6940 Hardware Installation Guide
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