[ntp:questions] Meinberg NTP Software--Time Accuracy

Danny Mayer mayer at ntp.org
Sat Jun 27 19:16:45 UTC 2009

tglassey wrote:
> Danny Mayer wrote:
>>>>> By geography, just like the zones that were mentioned in the post
>>>>> above.
>>>>> However, they are more fine-grained, especially when compared with
>>>>> large zones like us or eu.
>>>> How are you going to know the geography. DNS clients does not supply
>>>> that information even if they knew it and it's certainly not part of
>>>> the
>>>> DNS protocol.
>>> Danny isnt the location data potentially available as part of HOST
>>> listings and Location Records?
>> What Host listings and Location Records? There are no such types
>> available in DNS and even if they were they would not be local to the
>> nameserver responding. In any case such records would be entirely
>> voluntary, ie never added to a nameserver anywhere.
> Ah, let me be clearer -  I didn't say lots of people were using it, and
> it is as well as defining Well Known Services. As it happens though
> there are some folks who do use these. Especially true with some of the
> military BF (battle field)  process equipment.

This makes no sense. The are no such types and so they cannot be used
even if they existed. Furthermore the only entry in the request is the
name for which an address is requested. The client does not even send
the request directly to the authoritative server. It makes a request via
a resolving server and that is the server that contacts the
authoritative server. The authoritative server has no knowledge
whatsoever not only of the client but what it intends to do with the
returned addresses.

As for Well Known Services I assume you are talking about SRV records
but those don't even come into the picture here. BF process equipment
don't use DNS for this kind of stuff. I suggest you pick up a good book
on DNS so you can understand how this works. DNS and BIND by Cricket Liu
is the usual recommendation but their are plenty of others.


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