NTP Question

Harlan Stenn stenn at nwtime.org
Thu May 2 01:54:29 UTC 2019


On 5/1/19 4:28 PM, Mel Beckman wrote:
> Harlan and Mehmet,
> 
> I can expand on one important reason that James only alluded to with his “Kepping the Auditors happy” comment.
> 
> Passing NTP through a firewall and then using that as a critical time reference source represents a huge security risk. Here’s one detailed explanation of that risk:
> 
> https://insights.sei.cmu.edu/sei_blog/2017/04/best-practices-for-ntp-services.html

I have some significant disagreements with some of the assumptions and
positions in that posting, for whatever that's worth.  And there are
some good points in there, too.

H
--

>  -mel
> 
> On May 1, 2019, at 3:48 PM, James R Cutler <james.cutler at consultant.com<mailto:james.cutler at consultant.com>> wrote:
> 
> On Wed, May 01, 2019 at 02:35:58PM -0700, Harlan Stenn wrote:
> - Why do folks want to have one or more NTP server masters that have at
> least 1 refclock on them in a data center, instead of having their data
> center NTP server masters that only get time over the internet?
> 
> Answers to that include:
> 
>   *   Keeping the Auditors happy
>   *   Knowing that “everyone does it” - the vendor told them so
>   *   Bragging rights (expensive hardware)
>   *   Being unbothered by fighting with facilities for building penetrations and antenna mounts
>   *   Misunderstanding the beauty and economy Dave Mills marvelous algorithms for consistent time based on multiple sources, even those connected via internet
>   *   Unwillingness or inability to leverage other local resources capacity to run ntpd with minimal impact in order to have a good constellation of local NTP servers
>   *   Willingness to farm out time service without doing a deep dive into why and how, just leaving the design to the appliance vendors
> 
> This covers most of what I have encountered in providing enterprise time services for $dayjob+clients. I probably left out some significant points, but it has been a few years...
> 
> 
> 
> 

-- 
Harlan Stenn <stenn at nwtime.org>
http://networktimefoundation.org - be a member!



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