Many Cisco switches do not have the ability to save time after a power cycle. For this reason it is probably best to use NTP to keep the time current.
In GWLab we decided to use our Microsoft Domain Controllers as time servers. The main reason for this is to ensure Active Directory logon attempts do not fail due to a time difference.
Here’s an example of how to configure a Cisco 2950 switch:
Config t
ntp server 10.1.1.203
ntp server 10.1.1.107
clock timezone EST -5
clock summer-time EDT recurring 2 Sunday March 2:00 first Sunday November 2:00
The first and second line set the ip addresses of the domain controllers to be our ntp servers.
By default time on the Cisco switch is kept in UTC format. So the third line in this config example offsets UTC by -5 (which corresponds to EST). Set this to the correct offset for your timezone.
We want to display time correctly during daylight savings time. In 2007 the daylight savings time was modified. The specifics were set that daylight savings time would begin on the 2nd Sunday in March and end the 1st Sunday in November at 2:00 am. The fourth line in this config example displays the timezone as EDT during daylight savings time.
Tags: cisco daylight savings time, Cisco NTP, cisco time offset, set time cisco switch