HP-UX Internet Services Administrator's Guide (May 2010)

(tick.CS.UNLV.EDU). As before, this is due to networking problems between client
and server (New York to Las Vegas, over 3000 km), not some fault with the NTP
implementation at either end. This time server at Columbia is currently synchronized
to NAVOBS1.MIT.EDU, but three others (marked with "+" in column one) are attractive
and could step in immediately if NAVOBS1 failed for any reason.
Example 3: Evaluating Time Servers in Australia
Look at a time server in Australia. Here are the details:
ntp.adelaide.edu.au (129.127.40.3)
Location: University of Adelaide, South Australia
Synchronization: NTP V3 secondary (stratum 2), DECsystem 5000/25 Unix
Service Area: AARNet
Access Policy: open access
Contact: Danielle Hopkins ([e-mail])
/usr/sbin/ping ntp.adelaide.edu.au 64 5
PING huon.itd.adelaide.edu.AU: 64 byte packets
64 bytes from 129.127.40.3: icmp_seq=0. time=498. ms
64 bytes from 129.127.40.3: icmp_seq=1. time=500. ms
64 bytes from 129.127.40.3: icmp_seq=2. time=497. ms
64 bytes from 129.127.40.3: icmp_seq=3. time=498. ms
64 bytes from 129.127.40.3: icmp_seq=4. time=496. ms
----huon.itd.adelaide.edu.AU PING Statistics----
5 packets transmitted, 5 packets received, 0% packet loss round-trip (ms) min/avg/max = 496/497/500
Assume you are located in western United States and you ping this time server. The
ping round-trip times are much larger; around 500 milliseconds. Do not use a time
server at this distance unless you are really need it and understand what 500
milliseconds step changes mean to your users and applications. However, depending
on your location, ping round trip times from this server may be acceptable levels. The
round-trip times from your own location might be much smaller. Also note that the
variation in round-trip times is small.
/usr/sbin/ntpq -p ntp.adelaide.edu.au
Getting Started with NTP 53