The NTP Pool of time servers has announced that they now have a collection of over 1,000 time servers in Europe alone. The NTP pool was set up to prevent NTP server abuse and to insure there is not too much strain on the stratum 1 time servers.
The pool is now so popular over one million users choose top get their timing sources from there as most of the stratum 2 NTP servers on the NTP pool website are free to use and access over the Internet.
The NTP Pool is an ideal location for those running single machines or smaller networks were security and accuracy is not really an issue, however, for those charged with running a secure network or where accuracy is really important then internet time servers should not be seriously considered.
Unfortunately Internet time services cannot be authenticated (NTP’s security measure) which can leave a machine vulnerable, furthermore, Internet time sources are outside of a network’s firewall so a port needs to be left open to allow the time server can network to communicate.
For those serious about synchronisation there is no alternative other than to invest in a dedicated NTP server that receives its time securely from either radio signals or the GPS network.