The system clocks on C&CZ managed Linux machines are being kept up to date by using the Network Time Protocol (ntp). Each machine checks at regular intervals its system clock with several designated machines on the network and adjusts their system clock when needed. Whenever the difference between the local system clock compared to the system clock of other servers gets bigger than half a second the clock will be adjusted. If the difference is smaller, the system clock will be adjusted in small steps by slowing down or accelerating a little, to avoid multiple large time adjustments. Because all systems adjust their system clock to the same ntp servers, all system clocks will eventually become synchronized. The local servers are ntp1.science.ru.nl and ntp2.science.ru.nl.

These two servers sychronize their system clock with external stratum 1 servers:

  • ntp0.nl.uu.net
  • ntp1.nl.uu.net

One of these ntp servers, the ntp1.science.ru.nl, is available for synchronizing the system clock of your machine.

External information: