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User feedback: using the host name instead of the IP works with
german carriers Telekom (D1), O2 and E-Plus.<br>
<br>
Only D2 (Vodafone) has not been tested yet, but I don't expect any
problems there.<br>
<br>
It seems there is no general need for the GPRSDNS parameter?<br>
<br>
Regards,<br>
Michael<br>
<br>
<br>
<div class="moz-cite-prefix">Am 25.09.2015 um 04:10 schrieb Mark
Webb-Johnson:<br>
</div>
<blockquote
cite="mid:B9F760EB-0652-4C4E-9EBB-DC553C931B0E@webb-johnson.net"
type="cite">
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While I agree about the TTL and possibility of badly configured
caching servers not honouring it, in the greater scheme of things
it is really irrelevant.
<div class=""><br class="">
</div>
<div class="">This last change of address was urgently made by
TMC, not realising it would impact us. It is only by blind luck
that they hadn’t released the old address back to the amazon
pool. If that had happened, every user would have had to
manually sms their cars to make the change.</div>
<div class=""><br class="">
</div>
<div class="">Luckily, they hadn’t released the address, so could
assign it to another VM. I then did a socat on that machine, to
forward the traffic to our new address. Then, some magic on the
ovms_server.pl to reprogram cars connecting from the old address
to switch to the new one. We’d done a similar thing a few years
back, so I knew it would work.</div>
<div class=""><br class="">
</div>
<div class="">Faced with that, a couple of hours of downtime, due
to a DNS switch, is not so worrying ;-)</div>
<div class=""><br class="">
</div>
<div class="">That said, I don’t see any option on <a
moz-do-not-send="true" href="http://register.com" class="">register.com</a> to
set the TTL. Seems fixed at 4 hours. I’ll check further.</div>
<div class=""><br class="">
</div>
<div class="">Regarding the change from server IP to server name,
I would be grateful if more developers could try it, around the
world. Let me know the results here. In particular, with the
popular carriers in USA and Europe. It would be vastly simpler
to just tell people to change to use a name, rather than messing
around with google DNS servers.</div>
<div class=""><br class="">
</div>
<div class="">Regards, Mark.</div>
<div class=""><br class="">
</div>
<div class="">
<div>
<blockquote type="cite" class="">
<div class="">On 25 Sep, 2015, at 12:17 am, HONDA S-2000
<<a moz-do-not-send="true"
href="mailto:s2000@audiobanshee.com" class="">s2000@audiobanshee.com</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class=""><br class="">
On Sep 24, 2015, at 5:46 AM, Collin Kidder <<a
moz-do-not-send="true" href="mailto:collink@kkmfg.com"
class="">collink@kkmfg.com</a>> wrote:<br class="">
<blockquote type="cite" class="">On Thu, Sep 24, 2015 at
5:38 AM, Michael Balzer <<a moz-do-not-send="true"
href="mailto:dexter@expeedo.de" class="">dexter@expeedo.de</a>>
wrote:<br class="">
<blockquote type="cite" class="">I just checked the DNS
record for <a moz-do-not-send="true"
href="http://tmc.openvehicles.com" class="">tmc.openvehicles.com</a>:<br
class="">
<br class="">
<a moz-do-not-send="true"
href="http://tmc.openvehicles.com" class="">tmc.openvehicles.com</a>.
14399 IN A 54.197.255.127<br class="">
<br class="">
I suggest reducing the TTL to 1 hour before we
recommend the change to<br class="">
users.<br class="">
</blockquote>
<br class="">
Keep in mind that much of the internet is ruled by
caching name<br class="">
servers that will be quite stubborn about having to
update their<br class="">
records. I seriously doubt that a TTL of 1 hour will be
honored by<br class="">
much of anything. You're lucky if the ISP name servers
bother to check<br class="">
for updates more than once or twice a day.<br class="">
</blockquote>
<br class="">
I'm fairly certain that there are no caching servers that
ignore TTL. It would thwart emergency services if short
TTL values were ignored. My ISP has changed my server ip
address only once, and they went through the same process
of shortening the TTL before the scheduled change, then
increasing it back to normal after the new ip address was
activated.<br class="">
<br class="">
The catch is that any change does not take effect until
the old TTL expires. The "14399" above is 4 hours. So, if
the TTL were changed to 1 hour, it would not take effect
on all caching servers until 4 hours later. At that point,
though, all DNS servers would be working with a TTL of 1
hour. The typical is more like 24 hours, so the 4 hour
entry above is rather short. If 24 hours were used, then
the ISP would need to start the process 24 hours early by
changing the TTL to 1 hour a whole day in advance of the
ip address change. But at long as you know the current TTL
and plan ahead, it's always possible to make a prompt
transition.<br class="">
<br class="">
Those name servers that only bother to check once or twice
a day are doing exactly as they're told, and will check
every hour if told to do so instead.<br class="">
<br class="">
Brian<br class="">
<br class="">
_______________________________________________<br
class="">
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<a moz-do-not-send="true"
href="mailto:OvmsDev@lists.teslaclub.hk" class="">OvmsDev@lists.teslaclub.hk</a><br
class="">
<a class="moz-txt-link-freetext" href="http://lists.teslaclub.hk/mailman/listinfo/ovmsdev">http://lists.teslaclub.hk/mailman/listinfo/ovmsdev</a><br
class="">
</div>
</blockquote>
</div>
<br class="">
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</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
Fon 02333 / 833 5735 * Handy 0176 / 206 989 26
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