This page contains information about the campus Network Time Protocol (NTP) server (ntp.illinois.edu).
Technology Services provides Network Time Protocol (NTP) servers that can be used to synchronize the time of other computers on campus. After you configure your system to use ntp.illinois.edu, your system will resolve (randomly) to one of the three Technology Services Stratum-2 time providers.
Security Warning:
If you are a campus system administrator, you should ensure that any NTP servers on your network are not utilizing ntpd to serve time. Publicly accessible NTP servers running ntpd may be susceptible to being used in Distributed Denial of Service (DDoS) attacks.
See NTP (on the Technology Services Security Wiki space) for more information & instructions.
For general information about NTP for system administrators, see the NTP Public Services Project website.
Configure your system to use ntp.illinois.edu.
net time /setsntp:ntp.illinois.eduNOTE: Users who who have personal firewall software may need to adjust their firewall's configuration to enable communication with an NTP server.
NTP is not the same as timed; timed uses a different protocol which our time servers do not support.
The three Stratum-2 machines set their own clocks accurately by referring to the campus Stratum-1 time source, which keeps time within about 20 microseconds of true UTC using a GPS receiver. GPS, the Global Positioning System, allows precise location of receivers anywhere on earth, and to do this the receivers must know exactly what time it is relative to the GPS satellites, so a useful side effect of precise GPS positioning information is that the receiver also gets to find out the exact time.
If there are applications on systems on campus that require time accurate to the sub-millisecond level, direct NTP peering with the Stratum-1 clock can be arranged; however for the vast majority of systems on campus, the time from the Stratum-2's is more than sufficient, resulting in a clock setting within ten milliseconds or so of the exact time.
If you're interested in general information on NTP, you can find an overview, history, the latest news, and other interesting references on the Network Time Foundation website.