nanog mailing list archives
Re: NTP Server
From: todd glassey <tglassey () earthlink net>
Date: Sun, 24 Oct 2010 16:44:32 -0700
On 10/24/2010 7:37 PM, Peter Lothberg wrote:
acquired the time from the three stratum-1 clocks, they all poll each other for the average.How many clocks/servers do you need to average from to knew that you are within say 1ms of UTC(nist)?
What type of evidence model do you need to prove this with? - The NIST servers located around the US are mostly operated out of people like our operations (we have seven of them now and Atlanta coming online in about three weeks as well.) NTP has some foibles most are probably unaware of - that is it must have three (3) competent sources defined so that it can vote. We like to also say all three voices need to be coming from the same subnet so that the network latency and other physical aspects which control the policy-implementation are reliable as well. If you take one server from multiple sites you will be stuck with multiple network latency overhead factors polluting the resolution and certainty in the 'small bits' of your time-attestation. The real issue is how you prove the time-setting took. Or better yet - that you allow Applications to make their own NTP queries of reference time servers - that's really where the rubber meets the road in time-centric trust models. Todd Glassey
-P
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Current thread:
- NTP Server Brandon Kim (Oct 24)
- Re: NTP Server Peter Lothberg (Oct 24)
- Re: NTP Server Ben McGinnes (Oct 24)
- Re: NTP Server Eugen Leitl (Oct 24)
- Re: NTP Server Ben McGinnes (Oct 24)
- RE: NTP Server Brandon Kim (Oct 24)
- Re: NTP Server Cutler James R (Oct 24)
- Re: NTP Server Steven Fischer (Oct 24)
- Re: NTP Server Peter Lothberg (Oct 24)
- Re: NTP Server todd glassey (Oct 24)
- Re: NTP Server Ben McGinnes (Oct 24)
- Re: NTP Server Peter Lothberg (Oct 24)
- Re: NTP Server Bret Clark (Oct 24)
- Re: NTP Server Joel Jaeggli (Oct 24)
- Re: NTP Server Christopher Morrow (Oct 24)
- Re: NTP Server Tony Finch (Oct 25)
- RE: NTP Server Brandon Kim (Oct 24)