An Acronym for Network Time Protocol.

A method for synchronising a computer's internal clock (and system time) with an external source, such as a computer with a more accurate clock.

Machines that are synchronised with an atomic clock or GPS are stratum 1. Machines that synchronise to these machines are stratum 2, and so on. Normally stratum 1 machines aren't available for public connections.

Have a look at a the following page for a list of the stratum 1 time servers http://www.eecis.udel.edu/mills/ntp/clock1a.html . Or the following for a list of the stratum 2 time servers, http://www.eecis.udel.edu/mills/ntp/clock2a.html

NTP in NewZealand

Have a look at http://www.cosc.canterbury.ac.nz/paul/tr-cosc.01.99.pdf for a scientific study (from 1999) of the topology of the country's main ntp servers. (A bit dated as GPS is much more widely available now).

Stratum 1 NTP servers

Clear generously provides a stratum 1 NTP server for public use:

1. bigben.clix.net.nz

However, you really shouldn't synchronise to a stratum one server for your small network - if everyone did that then the the server would probably need too much bandwidth. Please read http://list.waikato.ac.nz/pipermail/nznog/2001-October/003705.html. The difference in accuracy between syncing to a stratum 1 server and a lower stratum server is negligible!

Some NewZealand ISPs have NTP servers for their customers:

1. ntp.maxnet.co.nz
2. ntp.iprolink.co.nz
3. ntp.iconz.co.nz
4. tk1.ihug.co.nz to tk4.ihug.co.nz
5. time.paradise.net.nz

or you could try querying your ISP's DNS servers with "ntp" or "ntp1".

Many of NewZealand's Universities also have public time servers such as:

• ntp.public.otago.ac.nz (Please notify before using)
• ntp.massey.ac.nz (Open Access, use DNS, changed IP recently and now hosted by two machines)

WaikatoUniversity no longer provides public access NTP servers, although they used to have

• truechimer1.waikato.ac.nz
• truechimer2.waikato.ac.nz
• truechimer3.waikato.ac.nz

If you live in Germany (or somewhere close by) you may want to try this list:

• time1.rrz.uni-koeln.de
• time2.rrz.uni-koeln.de
• time3.rrz.uni-koeln.de
• ts-1.rz.rwth-aachen.de
• ntp1.t-online.de
• www1.rrz.uni-koeln.de
• hora.cs.tu-berlin.de
• rustime01.rus.uni-stuttgart.de
• rzfs2.rz.tu-bs.de
• ns1.hrz.uni-giessen.de
• ntp2-rz.rrze.uni-erlangen.de
• mailbox.tu-berlin.de
• ntps1-0.cs.tu-berlin.de
• ntp0.fau.de
• ntp1.fau.de
• ntp2.fau.de
• ntp3.fau.de
• ptbtime1.ptb.de
• ptbtime2.ptb.de
• Another very extensive list of public German NTP servers can be found at http://www.hullen.de/helmut/filebox/DCF77/ntpsrvr.html

otherwise you could look for public servers on the internet on pages such as http://www.eecis.udel.edu/mills/ntp/clock2a.html.

Related pages: HowToClock?, HowToTimePrecisionHOWTO?, ntpd(1), ntpdate(1), hwclock(8)

Part of CategoryNetworking