2960 - NTP Commands

You can manually set the time with:

show clock [detail]
clock set [hh:mm:ss] [month] [day] [year]

But, if you're going to use a Cisco 2960 as an local NTP server, its a good idea to have it reference something else!

Google has public NTP servers that SMEAR TIME: time.google.com at 216.239.35.0 , time2.google.com at 216.239.35.4 , etc.

1 Configure a default gateway (if required), and make sure we can ping the time server (eg, google: 216.239.35.0):

2960#en
2960#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
2960(config)#ip default-gateway 10.10.10.254
2960(config)#do ping 216.239.35.0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 216.239.35.0, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 122/322/1119 ms
2960(config)#

2 Set the NTP reference server:

2960(config)#ntp server 216.239.35.0 prefer
2960(config)#do sh ntp status
Clock is synchronized, stratum 5, reference is 216.239.35.0
nominal freq is 286.1023 Hz, actual freq is 286.1023 Hz, precision is 2**21
ntp uptime is 1583123700 (1/100 of seconds), resolution is 3496
reference time is E9CA5041.C5FD3468 (11:42:25.773 UTC Wed Apr 17 2024)
clock offset is -10816782.1259 msec, root delay is 125.89 msec
root dispersion is 10817034.85 msec, peer dispersion is 187.55 msec
loopfilter state is 'SPIK' (Spike), drift is 0.000000000 s/s
system poll interval is 64, last update was 11 sec ago.
2960(config)#exit
2960#sh ntp associations

  address         ref clock       st   when   poll reach  delay  offset   disp
 ~127.127.1.1     .LOCL.           7      5     16     3  0.000   0.000 3937.5
*~216.239.35.0    216.239.0.253    4     18     64     1 120.75   1.828 1937.5
 * sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured

3 NTP time is always UTC, so if you're anywhere else in the world, you'll need to set your timezone and UTC offset.

2960(config)#do sh clock
12:54:55.087 UTC Wed Apr 17 2022
2960(config)#clock timezone UTC +2

To specify time zone and daylight settings two commands are used:

2960(config)#clock ?      
   summer-time     Configure summer (daylight savings) time
   timezone        Configure time zone

Time zone configuration requires 2 parameters:

clock timezone zone hours-offset [minutes-offset]

Summer-time configuration can be either recurring or date-specific:

clock summer-time zone recurring [week day month hh:mm week day month hh:mm [offset]]
clock summer-time zone date date month year hh:mm date month year hh:mm [offset]

Eg:

2960(config)#clock timezone NYC -5
2960(config)#clock summer-time NYCDST recurring 2 Sun Mar 2:00 1 Sun Nov 2:00

Refer to the following for timezone info and zone abbreviations: