[ntp:questions] NTPv4 Peer Event Codes - secret decoder ring sought

David Mills mills at udel.edu
Fri Mar 19 00:14:55 UTC 2010


Joe,

You and Dave are working way too hard. The bits and pieces are 
documented on the ntpq page and on the Event Messages and Status Codes page.

RFC-1305  was written in 1992. It's been 18 years since then, so you 
should expect changes from time to time. Changes are not done lightly; 
they reflect updates in the algorithms and interpretation of the 
statistics and state variables. If the interpretation  has not changed, 
the name and code have not changed. If it has been changed or has become 
obsolete, the name is not reused.

Dave

Joseph Gwinn wrote:

>In article <46f5ae0a-93d6-44ea-812f-e4da2ae2c8a6 at a16g2000pre.googlegroups.com>,
> Dave Hart <davehart at gmail.com> wrote:
>
>  
>
>>There were backward-incompatible changes on May 13, 2008 for ntp-dev
>>4.2.5p114:
>>
>><http://ntp.bkbits.net:8080/ntp-dev/?PAGE=cset&REV=48295cccnu3e5cmGhOzAS7hA-pVG3A>
>>
>>Once again statestr.c is your friend:
>>
>><http://ntp.bkbits.net:8080/ntp-dev/libntp/statestr.c?PAGE=diffs&REV=48295137L4-SOuAy6YZauDbZtW6DRg>
>>
>>If you want to be able to decode these bits for ntpd versions from
>>before and after the change correctly, you need to query the version
>>string of ntpd, sadly, such as with:
>>
>>ntpq -c "rv 0 version"
>>    
>>
>
>So that's how you get the NTP version (rather than the ntpq version)!
>
>When our sysadmins first installed NTPv4, they used the version command of ntpq, 
>which said "4".  Check!  
>
>I came by a few days later to look at the purported NTPv4 loopstats and 
>peerstats files, and (ever suspicious) checked to see what version of NTP had in 
>fact generated them.  Still NTPv3.  The sysadmins had been snookered by ntpq, 
>which failed to make unambiguous whose version it was reporting upon.  
>
>This had also happened to me back in the days of NTPv3, but I was saved because 
>I knew that "4" could not be the answer.  But I never did figure out how to get 
>ntpq to tell me the version of the ntp daemon. 
>
>
>  
>
>>and then parse for 4.2.5p114 or later.  The format for the version
>>string can include an optional -RC# suffix, and before long, there may
>>be releases with a -beta# suffix in the -stable branch, such as
>>4.2.6p2-beta1 as a prelude to 4.2.6p2-RC1.
>>    
>>
>
>Still evolving, rapidly.  OK.  I will have to find out exactly which version I 
>have.  I have no need to decode status from prior versions.  I need only to 
>understand the status codes from what I am running, to understand what is and is 
>not working in my system.  Fixes have included giving NTP and related traffic 
>its own dedicated LAN and LAN ports on the hosts, to reduce buffeting of NTP 
>packets and/or the daemon by unrelated but heavy packet traffic.  The buffeting 
>causes what appear to be large, random, and often asymmetric transport delays.
>
>Is there available a written discussion of which changes were made and why?  
>This could be worth reading.
>
>More generally, these backward-incompatible changes will cause great confusion 
>and difficulty in transitioning to NTPv4 unless ntpq is kept up to date, and the 
>descriptions of what the various status codes mean are both complete and correct 
>- telegraphic summaries are not usually enough for non-developers to understand.
>
>Looking at the code you suggested, I also see that the variable names are the 
>same as in NTPv3 (and the names imply the original NTPv3 meanings), but the new 
>NTPv4 comments on those variables seem to contradict the meanings implied by the 
>names.  Not knowing the history makes it difficult to figure out just what is 
>now meant.
>
>Thanks,
>
>Joe Gwinn
>
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>  
>




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