[ntp:questions] Using two NTP Server: Bad?

unruh unruh at wormhole.physics.ubc.ca
Sat Apr 23 06:48:40 UTC 2011

On 2011-04-23, Hal Murray <hal-usenet at ip-64-139-1-69.sjc.megapath.net> wrote:
>>> Consider that "failure" here encompasses "serves bogus time".  Suppose
>>> you have 7 sources configured and 4 of them cluster nicely around an
>>> incorrect time, with 3 clustered around UTC.
>>I suppose it's possible but I'm not going to hold my breath waiting for 
>>an instance to appear!
> All it takes is a firmware bug and to have several NTP servers
> using the same GPS device with the bug.

What good will having more servers do then? If the probablility of 4 bad
ones is that high, the probability of 5 out of 9 is also high, and 6 out
of 11. Ie, in that case you are basically screwed. Of course everyone
could just use the national time standards servers-- they are not liable
to be wrong (maybe just overloaded).


More information about the questions mailing list