Since 2003 I deliver stratum 1 ntp time stamps to the internet community.
At that time I was proudly one of the first public stratum 1 IPv6 ntp servers in the world.

It is my goal to deliver stratum 1 time stamps as accurately as possible for free and
with ‘homebrew’ equipment through a normal ADSL internet connection.

Due to my accuracy and uptime I am remotely monitored as of June 18th, 2008.

Update: In October 2013 I bought a Raspberry Pi as replacement for my
dedicated FreeBSD (thermostatised) setup, as the Raspi consumes <4 Watts. is an early server in the NTP-pool,
and (now/still) serves >1000 clients world wide.

Accuracy of aardbei (‘strawberry’ ;- ), my open access pool stratum 1 NTP server,
disciplined by Linux, a Motorola Oncore UT+ GPS derived PPS , and .. . Guzzi,
not sleeping there anymore, and the antenna is on my roof ; -)

Technical details / specifications:, ntpd-4.2.6p5 with (nano) Linux-PPS running on a Raspberry Pi
(model B, 512 MB RAM, 900 MHz, 8 GB SD-card).

External discipline for
GPS + PPS: Motorola Oncore UT+ GPS timing receiver
CET (backup): DCF77 receiver module

Access policy for ntp* time/ntp servers:
Open access, but…. please notify ntp @ for permanent associations
e.g. when you run a ntp server and want to use ntp* as stratum 1 reference(s).
Please no bursting. Do not poll more than once per 64 secs (i.e. minpoll 6).

Although ntp* machines try to be as accurate as possible,
NO rights and/or responsibilities can be derived from these free ntp* services.


  • 2013 okt: bought a Raspberry Pi, implemented the PPS_GPIO patch, which
    works with an inverter (transistor) to produce UTC epoch time stamps with
    remarkable accuracy (the Raspi is not thermostatised yet…) and contributes
    to a sustainable world, i.e. power consumption is <4W (instead of ~50W for my old setup).
  • 2009 dec: upgraded both and to ntpd-4.2.6
  • 2008 nov 15: upgraded ntp2 from DCF77 to GPS timing and added stats here
  • 2008 june 12: FreeBSD 7.0 with PPS_SYNC and Jupiter GPS is now the primary ntp server.
    Stats can be viewed here.
  • 2008 june 07: lithium has one DCF77 receiver but two drivers. GENERIC (DCFa) and radioclkd2 (DCFb).
  • 2008 may 02: switched to LinuxPPS *and* low level IRQ patched kernel
  • 2008 apr 16: switched to Motorola Oncore UT+ timing receiver for helium and back to LinuxPPS
  • 2008 mar 24: changed reference for lithium from CET (DCF77) to GMT (MSF60)
  • 2008 mar 23: upgraded to ntpd-dev-4.2.5p113, and switched to shmpps (refid GPPS)
  • 2008 feb 28: reconnected Jupiter Rockwell GPS (refid GPPS)
  • 2008 feb 23: connected Rubidium standard (refid Rb87)
  • 2008 feb 21: added traffic stats (packets/sec)
  • 2008 feb 18: ntp packets have minimal delay in HTB (“wondershaper“) queues:
  • # NTP (UDP protocol 17, port 123):
    tc filter add dev $DEV parent 1:0 protocol ip prio 10 u32 \
    match udp dst 123 0xffff \
    match ip protocol 17 0xff flowid 1:10