The Network Time Protocol (NTP) is a mechanism for synchronising the time on computers. When the full NTP implementation is used, it is capable of maintaining the same time on two computers with an accuracy of around 1 ms - 30 ms despite the varying delays in internet propagation.
Further information about NTP can be obtained from the main NTP website at http://www.ntp.org/(external link)
Notification of changes to NTP Service
Due to a service upgrade, IP address "18.104.22.168", and names "msltime.irl.cri.nz" and "msltime1.irl.cri.nz" will no longer be available for accessing MSL NTP services after 13:00 NZDT on the 30th of November 2022 (00:00 UTC, 30 November 2022). However, the NTP names "msltime.measurement.govt.nz" and "msltime1.measurement.govt.nz" will remain available for the foreseeable future, and will be set up as aliases of "pool.msltime.measurement.govt.nz" after this date. It is also highly recommended that you update your NTP configuration to use "pool.msltime.measurement.govt.nz" to access MSL's NTP services.
MSL operates a pool of stratum 1 servers with the name pool.msltime.measurement.govt.nz and address 22.214.171.124.
Access to individual servers in the pool is managed by a load-balancer running on our corporate IT infrastructure. The servers in the pool are managed by Measurement Standards Laboratory. Using a pool ensures NTP clients should always be able to obtain an NTP server, with a fixed IP address, while allowing Time Standards staff to take individual servers offline if necessary.
The MSL NTP servers are synchronised using a 1 pulse per second signal to the New Zealand Time Standard. The server time is typically stable with respect to the time in the caesium clocks to around 1 microsecond, but the variability in the network delays limits the accuracy for remote clocks/clients.
The servers are publicly available to all connections from within NZ. But please note, these servers only respond to NTP and "Simple Network Time Protocol” (SNTP) requests. They do not respond to "datetime" requests.
MSL's Stratum 1 NTP servers are currently open-access but serious users, those for whom time is important, are encouraged to register their use by sending the (static) IP address of their server(s) and a contact email address to email@example.com to receive service notifications and in case we need to restrict access in the future. Please limit access to three servers and make any additional connections to what will be stratum 2 servers.
Please contact us if you have any queries about this service.