Dear All
Many thanks for the huge number of quick and informed responses to
this original question:
> We have a network consisting of mainly NT and DU 4.0b boxes (also
> AIX and HP). We have one NT server in particular which gives the
> system time to all the NT clients. I would like to find a way of
> synchronising the time on the unix boxes with this NT server.
> Could anyone point me in the right direction?
Thanks, so far, to:
Peter Stern
Thierry Holzer (for two replies!!!)
Steve Gwynn
Brad Alexander
Tom webster
Graham (ALLAN_at_mnhep1.hep.......)
H. Blakely Williford
Christopher Davis
Franco Tassone
susrod_at_hbsi.com
Sam Nelson
The overwhelming suggestion was to use ntp which has good manual pages
under ntp and xntpd and which is setup using ntpsetup.
People mentioned a number of bits of NT ntp client software: Steve
Gwynn suggested TARDIS/TARDISNT which is shareware and should be
available from your favourite 32 bit download site. Christopher Davis
mentioned Dimension 4 which is available from
http://www.thinkman.com/~thinkman/.
The most detailed replies came from Thierry Holzer and Tom Webster and
I have included both in full below. Many thanks again to all who took
the time to reply.
Nick
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Thierry Holzer wrote:
Basically, NTP software exist in 2 forms: clients ('ntpdate') and
servers ('xntpd').
The client is quite easy to understand, it is the same as 'rdate' or
'net time': you run this at boot time or in crontabs.
The servers keep sync'ed with other servers *permanently*, with both
'vertical' and 'horizontal' organization.
By 'vertical' I mean a supposedly 'better' time reference, by
'horizontal' I mean several servers kept in sync together using
broadcasts and/or multicats.
'Horizontal' is 'inside same stratum' in NTP parlance, 'vertical'
crosses 'stratums' using 'better' NTP servers, or interface with
external hardware 'clock' (system clock, radio, atomic clock, ...).
Now, forgetting for a while whatever mecchanism that syncs your
Wintel clients with your NT time server, you may:
1) keep your NT time server as the NTP time server for your Unix
machines.
You then need to run xntpd on your NT time server, and this xntpd
would use the NT time server clock as its source ('vertical' sync).
The Unix machines would run an NTP client (eg. crontab) to keep in
sync with the NT time server.
2) run xntpd on several Unix machines *and* on your NT time server,
have them sync'ed together, and have a reference clock on one of
these machines (eg. the NT time server system clock).
3) run xntpd etc. (same as above), and have a external NTP reference
'clock' oustside your network (cross-stratum).
What we do here is 3):
* 2 xntpd kept in sync with public NTP servers (therefore we
indirectly are sync'ed with atomic clocks) using unicast IP
* Unix and NT servers running xntpd, sync'ed altogether using
multicast IP and having the above mentionned 2 NTP 'master' servers as
reference
* the rest of the machines (Unix, NT servers, Win* clients) run NTP
client at boot time and via crontabs/at service.
If you need more practical info on NTP software for Win* and NT
machines, my colleague Fabrice Clement <Fabrice.Clement_at_ceram.fr> has
done the job.
For Unix machines, xntpd comes with DU (see ntpsetup), but anyway
compiling the source is straightforward.
Only older flavours of Unix make xntpd unable to change their system
clock (missing or buggy system call). Workarounds are included in
xntpd distribution.
===========================================================#
Tom Webster wrote:
Please forgive me, but I have to say that this is ack-bassward for 95%
of folks. The windows "net time" synch is accurate to within a second
or two, while NTP tends to be accurate down to the millisecond level
(depending on your hardware).
What time source are you using to sync your NT server? If you are
going out to the net to using NTP or are using a time reciver
(basically a radio with a serial port that receives a time sync signal
from an
atomic clock), I would strongly advize doing one of the following:
1. Sync time on the two platforms independantly. This works nicely
if you have a full time link to the net. Just setup ntpd on one or
two of your UNIX systems and have the other UNIX boxes sync to them.
2. Setup NTP on one of your UNIX boxes, two is better, then run samba
on the boxes. Sync UNIX boxes to these systems using ntp and windows
boxes via "net time".
3. Setup NTP on one or two of your UNIX boxes. Sync UNIX boxes to
these
systems using ntp and use one of the shareware NT NTP clients to sync
your NT server to the UNIX boxes. There is a lousy client provided
with the resource kit, but you would do better with one of the third
party ones.
4. I think there are some NTP implementations on NT that can work as
lower tier NTP servers. You could run one of these on the NT box and
sync your UNIX boxes to it. This wouldn't be my choice, as PC clock
hardware tends to be MUCH worse than those on UNIX workstations.
If you just set your systems agains your wrist-watch once a month or
so, see if you can find an NT implementation of timed that will act as
a server. The use of timed is depriciated because it isn't much more
accurate than NT's "net time", but it should work well enough if you
just need the systems to be within a second of each other, but not
dead on 'real time' -- i.e. it's OK if all of the systems are 5
minutes off of what the time should be, as long as all of them are the
same.
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Received on Mon Jun 08 1998 - 11:23:39 NZST