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New Member

Using NTP on a router...

I want to synchronize time between my router / switch with a Win2k machine that is already pulling time from an external source. I understand that a network device will not pull time from a Win2k machine...

Can anyone recommend a product that does this (preferably free)?

...And what is the best way to set up my routers & switches to get their time synchronized?

Thanks in advance for your comments.

9 REPLIES
New Member

Re: Using NTP on a router...

On our network, I have my core switch synchronize its time from the Internet and all other switches get their time from it. Try this link.

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_6_2/confg_gd/ntp.htm#xtocid296436

New Member

Re: Using NTP on a router...

Thanks for the input...

But I am looking to specifically synch from a router / switch to a Win2k machine that is synch to an exteranal source. I do not want to have to open up ports thru my firewall that I do not have to- when there is a server that is already getting the information I need.

Re: Using NTP on a router...

If i understand correctly you are wanting to sync you win2k Machine to the router, is thats the case the Cisco router (preferably i higher end one) can be an NTP server or an SNTP server for low end devices.

Here is a good paper to get you started:

http://www.cisco.com/warp/public/126/ntpm.html

You will need a NTP client on your WIN2K machine which is available on the WEB here http://www.eecis.udel.edu/~ntp/

If you wanting the router to sync to WIN2K then you will need an NTP server on WIN2K available form http://www.eecis.udel.edu/~ntp/

Hope this helps

Regards

New Member

Re: Using NTP on a router...

thanks for the info.

I do want my router to sync with a Win2k machine, but when I go to the link you provided the application you are suggesting looks like its a unix app. I can't seem to find the instructions for a Windows port.

Do you have any insight on how to get this installed to work on Win2k - or am I simply looking at the wrong product?

Re: Using NTP on a router...

I have not seen S/W that will take the BIOS/Windows time as a stratum 1 or 2 clock. So it would be easier to have the router provide CLOCK and get an NTP client for the Win2K box which are freely available

Here is a reference that might help you, most people have a radio link to some sort of stratum 1 clock

http://www.galleon.eu.com/computer-time-clock.htm#Windows2000

New Member

Re: Using NTP on a router...

Thanks again.

I am trying to do what you haven't seen yet. I need a router to sync off of a Win2k device , not the other way around. I am surprised there is not a app out there that does that- atleast, I am having all kinds of trouble finding one- if there is.

I'll kep digin...

If I set a router to be the server is the comman simply ' ntp server x.x.x.x ' or do I use the master option?

Does the router have to sync with something or will its peers just grab the local time from the router?

... I may just set my router as the server and have my other network sevices sync to it.

Re: Using NTP on a router...

Well unless you find the S/W or buy the S/W and cards you will have a problem.

In the mean time to config the router you will ahve to use the ntp master command:

Eg: on NTP server (Router)

clock timezone GMT 0

clock summer-time BST recurring

ntp master 3 (Stratum 3)

ntp update-calendar

sh clock

15:31:45.483 BST Fri Sep 27 2002

sh ntp stat

Clock is synchronized, stratum 1, reference is .LOCL.

nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**24

reference time is C13EEA23.EA7FD259 (15:30:59.916 BST Fri Sep 27 2002)

clock offset is 0.0000 msec, root delay is 0.00 msec

root dispersion is 0.02 msec, peer dispersion is 0.02 msec

sh ntp assoc

address ref clock st when poll reach delay offset disp

*~127.127.7.1 .LOCL. 0 53 64 377 0.0 0.00 0.0

* master (synced), # master (unsynced), + selected, - candidate, ~ configured

On the client side:

clock timezone GMT 0

clock summer-time BST recurring

ntp update-calendar

ntp server 192.247.3.15

sh ntp sta

Clock is synchronized, stratum 2, reference is 192.247.3.15

nominal freq is 250.0000 Hz, actual freq is 249.9999 Hz, precision is 2**24

reference time is C13EEA8B.66BDCB21 (15:32:43.401 BST Fri Sep 27 2002)

clock offset is 1.5657 msec, root delay is 1.14 msec

root dispersion is 2.01 msec, peer dispersion is 0.43 msec

sh ntp ass

address ref clock st when poll reach delay offset disp

*~192.247.3.15 .LOCL. 1 43 64 377 1.1 1.57 0.4

* master (synced), # master (unsynced), + selected, - candidate, ~ configured

Regards

New Member

Re: Using NTP on a router...

THanks, I will give that a go and see what comes of it. I appreciate your input.

Regards.

New Member

Re: Using NTP on a router...

You can run the same xntpd daemon on your w2k box that the unix boxes use. The latest Windows port can be found at: http://www.five-ten-sg.com

Ideally the w2k box will sync to two or more ntp servers. Either at your ISP or public stratum 2 servers. Lists of public stratum 2 servers and everything you ever wanted to know about ntp can be found here: http://www.eecis.udel.edu/~ntp/

Greg

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