# ntp server and client does not sync



## spring_64 (Apr 8, 2018)

I have a Freebsd 9.2 system and a cisco router. I enable and config my system as a ntp server. The cisco is ntp client and by ntp broadcast I want to sync both system's date and time. My problem is cisco is one houre behind!

Do you have any idea for this problem?


----------



## ShelLuser (Apr 8, 2018)

Start by upgrading your FreeBSD version to either 10.4 or 11.1. 9.2 has past its End Of Life a long time ago and is no longer supported.

Either way, a one hour time difference often hints at a daylight savings issue.


----------



## spring_64 (Apr 8, 2018)

ShelLuser said:


> Start by upgrading your FreeBSD version to either 10.4 or 11.1. 9.2


I have to use FreeBSD 9.2 and I cannot upgrade it.
I changed client time zone and the client time sync with server time.
Now I have some questions:
1. When I change server time with date command, should I restart ntpd daemon or it checks server time periodically?
2. When I change server time below one hour I can see ntp packet on my cisco router but it doesnot change the cisco time, and if I change it more than one hour the packets dose not sent to cisco router.what is the reason?

Thanks a lot


----------



## ralphbsz (Apr 8, 2018)

Is the difference *EXACTLY* one hour (within a few seconds)?  Definite time zone issue.  Note that the definition of time zone has changed in various areas in the last few years (the US is one such area).  Most likely your old 9.2 installation has an incorrect time zone definition.  Time zone definitions are complex; they are stored in a directory of binary files, on my system /usr/share/zoneinfo has 476 files.  You could become an expert in how time zones are defined and managed, and correct all those files, but it would be much easier to use a modern installation.

Before you do anything else, make sure you have the correct time zone set on client and server, and you are running both with correct and up-to-date timezone definitions.  Without that, you'll just keep confusing yourself (and us).

You say you "changed client time zone".  What do you mean by that?  And then you say that the "client time sync".  How did you verify that?

Question 1: You changed the server time with date command.  Why did you do that?  You NTP server needs to have some source for setting its clock itself.  Usually, local NTP servers are themselves NTP clients, which usually synchronize to other (better) NTP servers.  For example, my home machine is set up to be the NTP server for everything inside the house, but it is also a NTP client, which is configured to get the time from us.pool.ntp.org.  Sometimes, NTP servers have their own source of accurate time; for example, one can now buy GPS receivers for less than $100 that are accurate to milliseconds and connect with serial (RS232) ports, and use those as a source of a pretty accurate clock.  Anyway, you did step the time forward with date.  That probably screwed up your NTP server.  I would definitely restart it.  Manually changing the server clock while a NTP server is running sounds risky, and you should probably stop doing it.

However, restarting your NTP server immediately causes a problem for the NTP client (your Cisco).  Often, NTP clients are configured to only be able to drift the clock very slowly (and catching up a while hour would take too long to be practical), but they can also be configured to make a big "time jump" when they start.  On FreeBSD NTP clients, you can configure that by setting the variable "ntpd_sync_on_start" to yes in /etc/rc.conf.  No idea how to do that on a Cisco.


----------



## SirDice (Apr 9, 2018)

spring_64 said:


> I have to use FreeBSD 9.2 and I cannot upgrade it.


Why can't you upgrade? FreeBSD 9.2 has been End-of-Life since December 2014.

Topics about unsupported FreeBSD versions


----------



## PacketMan (Apr 12, 2018)

Consider these kind of commands on a Cisco tradition IOS device.  (Cisco has many flavors of OS now, each with their own CLI structure.)
`clock timezone MST -7 0
clock summer-time MDT recurring`

Read the Cisco documentation online at Cisco.com. Just google it. It's not clear to me this is a FreeBSD issue.


----------

