Brocade VDX 8770-4 QuickStart Guide - Manual (Page 26)

26 of 32 Brocade VDX 8770-4 QuickStart Guide
Publication Number: 53-1002554-01
Setting the date and time
The MM maintains the current date and time inside a battery-backed real-time clock (RTC) circuit. Date and time are
used for logging events. Switch operation does not depend on the date and time; a Brocade VDX 8770-4 with an
incorrect date and time value functions properly. 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 a switch by using the clock TimeZone command. The time zone setting has the
following characteristics:
• The time zone 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.
The following regions are supported: Africa, America, Arctic, Antarctica, Asia, Atlantic, Australia, Europe, Indian, and
Pacific. One of these, along with a city name, establishes the time zone. Refer to
“Setting 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 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 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 either IPv4 or IPv6 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 configure terminal to change to global configuration mode.