Superseded by this http://ava.upuaut.net/?p=726
These instructions no longer work please review the article above.
EDIT : I’ve confirmed the version of NTP provided in the Open Chaos download below isn’t susceptible to the DRDoS / Amplification Attack using ntpdc monlist command discussed here : http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-5211
Working in IT I’m aware of how keeping accurate time is important, generally most of the time we will point our devices / equipment at uk.pool.ntp.org however there may be situations where a local time source is preferable. This can be for a number of reasons, where no internet is available, radio amateur’s doing meteor scatter etc.
David Taylor from Satsignal.eu has done a comprehensive write up of getting the Pi to work as a Stratum-1 NTP Server. Taking this work Hauke Lampe has created an image with all the hard work done. With no compiling to be done its possible to get a Pi working with as a Stratum 1 NTP Server in less than five mins.
First you need a Raspberry Pi GPS Addon board available at Hab Supplies. Secondly you need a patch antenna (see related products). Thirdly get the minimal SD-card image based on Raspberry Pi’s Raspbian “wheezy” distribution featuring PPS-enabled kernel and ntpd by Hauke here :
Pop the image on an SD Card. Plug in the antenna and the GPS board and power on the Pi.
Thats it really it will boot up and work as an NTP Server.
I run the following commands as well :
sudo apt-get update
sudo apt-get install raspi-config (Use Raspi-config to resize fs)
sudo apt-get upgrade
sudo apt-get install gpsd-clients
Please be aware if there is a new kernel it may over write the Kernel with PPS support in it. You can from here install SNMP, monitoring as per Davids page here : http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html
A nice cheap very accurate time server for less than £100!