Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Creating an NTP Server

Hi

I just started a new job and the want me to build an ntp server so that all the Cisco gear can get the correct time.

Can you tell me how would i go about creating this and my thanks in advance.

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Gold

Re: Creating an NTP Server

I wouldn't configure Cisco appliance as an authoritative NTP server.

If you have Windows servers, you can configure them to be an authoritative NTP server.

How to configure an authoritative time server in Windows XP
http://support.microsoft.com/kb/314054

How to configure an authoritative time server in Windows Server
http://support.microsoft.com/kb/816042

How to configure an authoritative time server in Windows 2000
http://support.microsoft.com/kb/216734

8 REPLIES
New Member

Re: Creating an NTP Server

link your device to stratum 0  on the internet. There are lot of them , just try google

for ntp server , use this command

ntp master
ntp update-calendar
ntp server 192.5.41.40 prefer
ntp server 192.5.41.209

New Member

Re: Creating an NTP Server

So let me ask you this, do i need to do these commands on a certain switch or router

Re: Creating an NTP Server

So let me ask you this, do i need to do these commands on a certain switch or router

Hi,

If you want on of your router to act as ntp server for your local lan devices then you need to configure the abobe commands on your core router or switch which will act as ntp server for lan devices.

configure ntp master 3 (startum value)

and in client as ntp "ip address" of the router or switch which  is reachble to sync with ntp master devices.

Hope to Help !!

Ganesh.H

Remember to rate the helpful post

Gold

Re: Creating an NTP Server

Check out fx meinberg NTP servers.

There are several good points to having a unit built for the task.

www.meinberg.de

easy to use, install and they are reliable.

HTH

Hall of Fame Super Gold

Re: Creating an NTP Server

I wouldn't configure Cisco appliance as an authoritative NTP server.

If you have Windows servers, you can configure them to be an authoritative NTP server.

How to configure an authoritative time server in Windows XP
http://support.microsoft.com/kb/314054

How to configure an authoritative time server in Windows Server
http://support.microsoft.com/kb/816042

How to configure an authoritative time server in Windows 2000
http://support.microsoft.com/kb/216734

Gold

Re: Creating an NTP Server

I would not use a Windows server for that if it is not designed for it from the beginning.

the reason for that is the same reason why we can not just set the time once and never have to do it again.

The server running the windows machine is not hardware corrected for the time drift,  ie the crystal supporting the time is not good/specific enough.

One of the reasons why you want a unit built for the task is that the crystals have much narrower tollerance levels than those of a normal server.

This means that it is much easier to get the wrong time.

I have seen servers go close to a minute wrong after as little as a month.

The meinberg NTP servers are just "normal" pc´s with linux but with higher tolerances and a radio for either GPS or radio correction.

HTH

Hall of Fame Super Gold

Re: Creating an NTP Server

You're right.  If I have a choice, I'd go for a GPS NTP server and not just an appliance with a need to go out and synchronize over the internet.

Hall of Fame Super Gold

Re: Creating an NTP Server

Thanks for the ratings.

1031
Views
0
Helpful
8
Replies
CreatePlease login to create content