NTP on 3750 Switch

Unanswered Question
Sep 2nd, 2008

Hi Guys, I'm trying to set my 3750 switch as an NTP server so that the surrounding network devices take time from it. I notice though when i add the 3750 as an NTP server on another switch, it does not sync although they are directly connected.

How do i verify that my 3750 is capable of pulling time from the internet, then serving as a host? (it doesnt support the NTP master command - although i will not use it)

this is my switch version outpu:

Cisco IOS Software, C3750 Software (C3750-IPSERVICES-M), Version 12.2(25)SEE2, RELEASE SOFTWARE (fc1)

Copyright (c) 1986-2006 by Cisco Systems, Inc.

Compiled Fri 28-Jul-06 08:46 by yenanh

Image text-base: 0x00003000, data-base: 0x010CE290

I have this problem too.
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satish_zanjurne Tue, 09/02/2008 - 01:32

Hi See configuration below..

*****For the Client*****

clock timezone EST -5 ????

ntp source loopback 0 ?????

ntp server ip_address key 1

!--- For the server:

clock timezone EST -5

clock summer-time EDT recurring 1 Sun Apr 3:00 last Sun Oct 3:00

clock calendar-valid

ntp source loopback0

ntp update-calendar

!--- This sends NTP broadcast packets.

ntp broadcast client

!--- This receives NTP broadcast packets.

jtphilies Tue, 09/02/2008 - 16:55

Hi Satish, thanks for your response. but half of those commands are not supported on my Switch.

wangyb Tue, 09/02/2008 - 22:31


You can verify the ntp is configurated successfully through the 'show ntp sta'..

for example:

DWTL_7F_3560#show ntp status

Clock is synchronized, stratum 4, reference is

nominal freq is 119.2092 Hz, actual freq is 119.2087 Hz, precision is 2**18

reference time is CC68AC26.75F29A0E (14:24:38.460 BeiJing Wed Sep 3 2008)

clock offset is 5.2167 msec, root delay is 290.73 msec

root dispersion is 106.69 msec, peer dispersion is 11.32 msec

DWTL_7F_3560#show clock

DWTL_7F_3560#show clock

14:25:22.872 BeiJing Wed Sep 3 2008


jtphilies Tue, 09/02/2008 - 23:30

Thank your Wangyb, i am aware of those commands. My 3750 is currently sycing time.

But when i config my 3560 to use the 3750 as the ntp server it does not sync when i do a #sh ntp ass


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