time sinchronization

Sun Feb 11 20:25:49 UTC 2007

Christopher,

Thanks a lot for your nice and detailed response. To others: kind thanks too.

It turned out that in my case it was just a matter of creating /etc/ntp.conf 
and adding an entry there. Hence, it looks like that ntpd is by default 
installed in ubuntu, simply not configured only.

Regards,
zb.

On Saturday 10 February 2007 17:00, Christopher Browne wrote:
> On 2/10/07, Zbigniew Koziol <softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org> wrote:
> > It did work on my computers in the past.
> >
> > Now, I maintain ubuntu server. That, it seemed, trivial thing, does not
> > look trivial anymore.
>
> I might wildly guess that this may be a case where Debian has
> introduced several packages and put some common config into one or two
> of them such that "fighting with the distribution" is getting you into
> frustration.
>
> > Would someone be kind enough to write a short, basic recipe for that?
>
> 1.  Install ntp
>
> apt-get install ntp
>
> 2.  Make sure it has some servers listed in /etc/ntp.conf
>
> There is a global pool of over 100 NTP servers that provide
> round-robin services via DNS; if you specify "pool.ntp.org", you'll
> use that pool, and not flood anybody.
>
> > What, if any, software should I install?
>
> ntp
>
> >Which ports should be opened?
>
> Port 123 needs to be open to UDP traffic.
>
> > How to synchronize from command line?
>
> For that, you need to install the separate package, ntpdate.
>
> If ntpd is NOT running, you can, as root, run:
>
> ntpdate pool.ntp.org pool.ntp.org myhost.org yourhost.org ...
>
> > Is time.nsrc.ca appropriate for using?
>
> Probably not, unless you're setting time for a large set of servers.
>
> You should probably use pool.ntp.org instead.
>
> Another entertaining option is to consider backtracing the servers
> nearby you in your network.
>
> For instance, if I trace a route out to somewhere (say slashdot), I
> find a whole bunch of routers in the way.  Many of them are Cisco
> routers that are running NTP.
>
> knuth:~# traceroute slashdot.org
> traceroute to slashdot.org (66.35.250.150), 30 hops max, 52 byte packets
>  1  godel (192.168.1.1)  0.369 ms  0.300 ms  0.298 ms
>  2  64.230.197.235 (64.230.197.235)  52.002 ms  52.169 ms  50.934 ms
>  3  dis26-toronto63_Vlan112.net.bell.ca (64.230.222.81)  49.018 ms
> 47.679 ms  50.631 ms
>  4  core4-toronto63_GE5-2.net.bell.ca (64.230.207.105)  51.990 ms
> 49.893 ms  50.249 ms
>  5  core1-chicago23_pos12-0-0.net.bell.ca (64.230.147.14)  60.330 ms
> 61.197 ms  57.883 ms
>  6  bx4-chicago23_POS3-0.net.bell.ca (64.230.203.50)  63.479 ms
> 60.386 ms  59.579 ms
>  7  dcr1-so-3-1-0.chicago.savvis.net (208.175.10.85)  60.268 ms
> 59.505 ms  93.675 ms
>  8  dcr2-so-2-0-0.Denver.savvis.net (204.70.192.133)  83.555 ms
> 85.276 ms  84.046 ms
>  9  dcr1-so-2-0-0.SanFranciscosfo.savvis.net (204.70.192.114)  126.579
> ms  128.396 ms  161.049 ms
> 10  dcr2-so-5-0-0.SanFranciscosfo.savvis.net (204.70.192.150)  126.611
> ms  126.159 ms  124.423 ms
> 11  bhr1-pos-0-0.SantaClarasc8.savvis.net (208.172.156.198)  128.546
> ms  125.492 ms  127.232 ms
> 12  csr1-ve243.santaclarasc8.savvis.net (66.35.194.50)  129.895 ms
> 128.189 ms  132.192 ms
> 13  66.35.212.174 (66.35.212.174)  132.563 ms  174.111 ms  128.656 ms
> 14  slashdot.org (66.35.250.150)  135.238 ms !C  128.849 ms !C  129.558 ms
> !C
>
> Turning this into an ntpdate request:
> knuth:~# ntpdate `traceroute slashdot.org 2> /dev/null | awk '{print
> $2}' | tr '()' ' ' `
> 10 Feb 16:50:43 ntpdate[19518]: adjust time server 208.172.156.198
> offset 0.000835 sec
>
> I'm not sure that's 100% 'kosher,' but if argued with, I could argue
> that these servers all volunteered to carry my traffic.  The argument
> would be stronger if I restricted the list to the Bell servers nearby,
> as I'm paying them for Internet services...
>
> At any rate, I'd suggest trying to have some diverse set of servers
> that *aren't* all the same tick/tock @ U(T).
>
> FYI, it seems like a waste of time to me to try to find a server
> geographically nearby.  When I run traceroute, I find that I need to
> go thru Chicago to get back to anything at U(T).  That's going to be
> common for anyone using Bell Sympatico.  I wouldn't be surprised if
> Rogers users would discover similar to be true.
>
> It appears that Sympatico hasn't any connections to the Toronto
> Internet Exchange (torix.net), which seems silly to me; there ought to
> be value to having direct quick access to geographically nearby
> servers around Toronto.  Of course, they've never been accused of
> being particularly bright...
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