Public IPv4/IPv6 Stratum 1 NTP Server


ntp.i2t.ehu.eus (or ntp.i2tv6.ehu.eus) is a public IPv4 and IPv6 ready Stratum 1 NTP server provided by the I2T Research Group of the University of the Basque Country UPV/EHU located in the Engineering School of Bilbao.

The NTP servers consists of one Intel Pentium 4 PC running Ubuntu Server LTS. The NTP daemon is the standard NTP daemon provided by the NTP Project and is configured with one Motoroloca ONCORE GPS for providing the preferred time source and additional Stratum 1 and Stratum 2 NTP servers for fallback purposes. We monitor the server using Icinga and Munin; and perform backups with backuppc. Finally, the server is connected to the network of the University of the Basque Country UPV/EHU.


On the one hand, if you are using the Spain or the Europe zones of the NTP Pool Project, you might already be using this public server without realising. Apart from this pool, this NTP server is also published in the list of public Primary Servers of the NTP Project.

On the other hand, if you prefer to use explicitely our NTP server in your devices, please follow the next premises. Please, take into account that there could be shutdowns of the service without previous notice:

  • Use preferibly domain names instead of IPv4/IPv6 addresses to configure our server becasue IPv4/IPv6 addresses could change. You have two options:
    • ntp.i2t.ehu.eus (preferred option): this domain name resolves to IPv4 and IPv6 addresses and your device will use any of them to connect to our server.
    • ntp.i2tv6.ehu.eus (use with caution!): this domain name only resolves to the IPv6 addresses of the server, so if you lack IPv6, you will not be able to reach our NTP server.
  • This NTP server is mainly focused on providing service to stratum 2 NTP servers; however it can also be used by other stratum servers and NTP client devices.
  • If you are going to configure this server in multiple NTP clients and servers, please consider to use your own NTP server and use our NTP server to provide time to your main NTP server.
  • You are free to use our NTP server and you do not need to send us any email to ask for it.



If you want to get in touch with the mantainers of the NTP server, you can send an email to the following addresses: eduardo.jacob(at).ehu.eus, christian.pinedo(at)ehu.eus, jon.matias(at)ehu.eus.