[ntp:questions] Bad NTP servers jeopardizing the pool.ntp.org initiative

Danny Mayer mayer at ntp.isc.org
Sat Mar 31 01:34:17 UTC 2007

Jan Ceuleers wrote:
> Wolfgang S. Rupprecht wrote:
> (I suggested that pool members with non-static IP addresses could be 
> accommodated by the pool).

Well you shouldn't have. It just won't work for any useful time period.

>>> And the protocol already exists: it's called dynamic DNS.
>> Care to flesh out how you envision this working?
> The pool is essentially a fancy name server. Pool members could use the 
> existing dynamic DNS protocol to register their current IP address with 
> the pool. Perhaps in addition to registering with their regular dynamic 
> DNS provider, if they provide services other than NTP.
> Advantages: dynamic DNS clients exist for lots of platforms.

Clients yes, servers no. The pool is a bunch of *servers* not clients so
why are you talking about the clients?

> Disadvantages: I don't know whether dynamic DNS servers are readily 
> available to be integrated with the rest of the pool server software. 
> Moreover, the pool would also need to use low TTL values (but then I 
> think it already is).

The only question would be if there are any *non*-dynamic DNS servers
readily available but why ask the wrong question.

> The other disadvantage is that pool clients might, for a limited period 
> of time, hammer whoever next receives the IP address previously held by 
> a pool server. Malevolant such inherintants of IP addresses might reduce 
> the perceived quality of the pool by telling the wrong time.

No, this isn't a limited length of time it's a long time, possibly
months until it ceases and even then maybe not. You should not be
guessing at the longevity of the provided IP address providing NTP service.


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