NTP syncing

Nifty Hat Mitch mitch48 at sbcglobal.net
Thu Sep 23 09:54:04 UTC 2004


On Wed, Sep 22, 2004 at 08:31:12PM -0400, Gene Heskett wrote:
> On Wednesday 22 September 2004 19:21, Nifty Hat Mitch wrote:
> >On Tue, Sep 21, 2004 at 10:34:23PM -0700, Kenneth Porter wrote:
> >> --On Tuesday, September 21, 2004 11:17 AM -0400 Gene Heskett
> >>
> >> >Verizon hasn't volunteered that they have one or more such
> >> > servers. For me, that would be very nice.
....
> >Another discovery trick is to use traceroute and use
> >ntptrace to inspect your nearby routers.  Most big name
> >routers supply ntp if so configured.
....
> 
> There was no response from any machine all the way to the secondary 
> dns.  

got to try... now we know.

> Starting locally on the primary traceroute list, I finally hit 
> one on the 17th hop but its a:
> stratum 16, offset 0.062642, root distance 0.006480

Not a problem ... if you traceroute to other 'interesting' places
you will get a different list of routers.  With a bit of attention
you can discover what is close to you.

> Which brings up 2 questions Tom,
> 
> 1. WTF is it 18 hops to my primary dns?

The net is getting BIG.

Name servers  and smtp boxes are commonly hunkered down 
in some far off 'safe' location.   If you run "dig" on
the IP address you posted from I find 
    ;; AUTHORITY SECTION:
    88.73.153.141.in-addr.arpa. 52848 IN    NS      ns1.bellatlantic.net.
    88.73.153.141.in-addr.arpa. 52848 IN    NS      ns2.bellatlantic.net.
And then dig on those name servers:
    ;; AUTHORITY SECTION:
    bellatlantic.net.       13149   IN      NS      ns4.verizon.net.
    bellatlantic.net.       13149   IN      NS      ns1.bellatlantic.net.
    bellatlantic.net.       13149   IN      NS      ns2.verizon.net.
    bellatlantic.net.       13149   IN      NS      ns2.bellatlantic.net.

So any three of these (ns[1234]) would be good in your /etc/resolv.conf.
Pick ones that have the most 'different' routes for reliability.
If you run dig on any of the dhcp assigned host names you are given
and look at the NS records you might locate some closer.

> 2. One would think that in 17 other machines, there would be a 
> timeserver.  Obviously these twerps aren't running a thing we don't 
> scream for.

Don't scream just ask.

In the case of NTP most router guys do not look on their
boxes as a service resource so they never think to turn ntp
on. As long as they route packets the other stuff is extra.

So, In your case use these three ntp hosts.
Yes all three.
  # http://www.pool.ntp.org/
  server pool.ntp.org
  server pool.ntp.org
  server pool.ntp.org

> Actually, there's a 3rd question: WTF if the secondary dns doing when 
> it attempts to contact my firewall box on a high port, 32,711 or such 
> as I posted last night?  I sent a nastygram to both postmaster and 
> abuse at the secondary dns's name, specifically requesting a reply, 
> but in 18 hours none has been forthcoming.  Should I just keep 
> beating on them till they get tired of me and disconnect me, or what?

Nastygrams only make support folk nasty.  In this case the details of
their network will be unknown to all but a handful.  It does not hurt
to ask but it is not worth a nastygram.

As long as the line gets you packets in and out for the right price,
not a problem.

A tool like firestarter has knowledge of common port use
and translates to human what it can.  The rest you need
to google.   As long as your firewall blocked the connection
... who cares.

Note that traceroute will generate icmp messages back to your box.  We
can start another thread to research and discuss that topic (routing and
icmp) if your Google efforts do not find good answers.

If /etc/services does not help look at header files like these:

   /usr/include/netdb.h /usr/include/netinet/in.h ... etc.

Programmers have done some homework on this stuff..


-- 
	T o m  M i t c h e l l 
	Me, I would "Rather" Not.





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