Operating System - OpenVMS
Showing results for 
Search instead for 
Did you mean: 

Pseudo NTP or faker NTP server ?

Thomas Ritter
Respected Contributor

Pseudo NTP or faker NTP server ?

Has anybody implemented an NTP server which can be used for testing ? We are looking at updating DTSS from NTP but want to test all the likely conditions.
Some test cases would be
-change the NTP time to the wrong year
-change the NTP time to the future and so on before we update DTSS.

Steven Schweda
Honored Contributor

Re: Pseudo NTP or faker NTP server ?

I'd assume that any NTP server could be used
for testing. You'd just need to run it on a
system where the time could be set to goofy
values, wouldn't you?

I haven't looked at it lately, but I should
still be running the DTSS$NTP_PROVIDER.EXE
(which I appear to have modified and built
around 25-SEP-2000 from code in [.DTSS] under
SYS$EXAMPLES). Call me gullible, but I just
trust the Department of Commerce time servers
to be more reliable than mine. (When they
hose _me_ over by propagating bad time
values, I'll be in good company, I reckon.)
Honored Contributor

Re: Pseudo NTP or faker NTP server ?

The code of the NTP reference implementations and related materials (formerly at UDel) are available at:


Have at.

RFCs are referenced there, so you can have a look at what's supposed to happen.

Re-code it locally to, well, "lie."

Or take a look at the ntpdsim tool lurking in the reference implementation.


Or set up your own NTP server using whichever IP stack (most include ntp servers), and configure your clients to listen to same. Then mess with the system time.
Honored Contributor

Re: Pseudo NTP or faker NTP server ?

Take a look at the NTP.CONF "local-master" directive.

On your NTP server you'll want to configure it this way - as a local-master clock. That will inform that server node that it is to use it own clock as being authoritative (at lest at the strata that you assign). You will then use a "server" directive in the NTP.CONFs of your client to reference the address of this server. For this testing, your server should specify only this "local-master" directive - and you need to assign the strata - perhaps something like "local-master 4" (in this instance the strata value is totally arbitrary though it must be an intteger less than 16). Then on your clients define only this server and no others.