[ntp:questions] Surplus Alpha as timeserver?

Tom Smith smith at cag.lkg.hp.com
Sat Mar 26 03:06:27 UTC 2005

Brad Knowles wrote:
> At 10:23 PM +0000 2005-03-25, Bjorn Gabrielsson wrote:
>>  Whats the general opinion. Should a public server be running nano
>>  kernal? or is that an overkill?
>     I'm curious.  I am reasonably familiar with the kernel architecture 
> of *BSD, and I'm pretty sure I have the basic knowledge of how the Linux 
> kernel architecture is laid out.  None of these involve micro or nano 
> kernels.
>     What are you thinking of, and how do you think that this will help 
> the security situation?
>     Note that OpenBSD now ships with their own NTP server OpenNTPd. 
> While I've said some pretty nasty things about it in the past, and while 
> I recognize that Darren has been working on making improvements, I do 
> not believe that OpenNTPd is yet ready for production use on a public 
> server.
>     I'm not sure how much luck you're going to get with the Reference 
> Implementation on OpenBSD, and I know you're not going to get any 
> support from the OpenBSD guys if you should happen to have any problems.

I'm really not sure what the kernel implmentations do or do not do
w.r.t security except that they move a lot of the details of PLL
maintenance out of user space, but of the possibilities you are
considering, Tru64 implments a pre-nano kernel. "options NTP_TIME"
together with "options MICRO_TIME" in the kernel configuration file
enables, respectively, the kernel PLL and microsecond interpolation
between the kernel ticks of 1/1024 seconds. The former option
is listed as an option when you build the kernel. The latter
you have to edit in by hand. Together with NTP V4 and a good
set of upstream servers or a reference clock, they
generally keep the clock strapped down to within a few hundred
microseconds or better of what NTP thinks the time ought to be.


More information about the questions mailing list