User guide

3-22 E
XTREME
W
ARE
S
OFTWARE
U
SER
G
UIDE
M
ANAGING THE
S
WITCH
C
ONFIGURING AND
U
SING
SNTP
To use SNTP, follow these steps:
1 Identify the host(s) that are configured as NTP server(s). Additionally, identify the
preferred method for obtaining NTP updates. The options are for the NTP server to
send out broadcasts, or for switches using NTP to query the NTP server(s) directly.
A combination of both methods is possible. You must identify the method that
should be used for the switch being configured.
2 Configure the Greenwich Mean Time (GMT) offset and Daylight Savings Time
preference. The command syntax to configure GMT offset and usage of Daylight
Savings is as follows:
config timezone <GMT_offset> {autodst | noautodst}
The GMT_OFFSET is in +/- minutes from the GMT time. Automatic Daylight
Savings Time (DST) changes can be enabled or disabled. The default setting is
enabled.
3 Enable the SNTP client using the following command:
enable sntp-client
Once enabled, the switch sends out a periodic query to the NTP servers defined later
(if configured) or listens to broadcast NTP updates from the network. The network
time information is automatically saved into the on-board real-time clock.
4 If you would like this switch to use a directed query to the NTP server, configure the
switch to use the NTP server(s). If the switch listens to NTP broadcasts, skip this
step. To configure the switch to use a directed query, use the following command:
config sntp-client [primary | secondary] server [<ip_address> |
<hostname>]
NTP queries are first sent to the primary server. If the primary server does not
respond within 1 second, or if it is not synchronized, the switch queries the
secondary server (if one is configured). If the switch cannot obtain the time, it
restarts the query process. Otherwise, the switch waits for the
sntp-client update
interval
before querying again.
5 Optionally, the interval for which the SNTP client updates the real-time clock of the
switch can be changed using the following command:
config sntp-client update-interval <seconds>
The default
sntp-client update-interval
value is 64 seconds.
6 You can verify the configuration using the following commands:
— show sntp-client