| Time synchronization can be a headache for many | | | | added to counter the natural slowing of the Earth's |
| network administrators attempting to synchronize a | | | | rotation. |
| network for the first time. There are many pitfalls that | | | | UTC is readily available as a time reference from a |
| an unaware network administrator can fall into when | | | | number of sources. The Internet is a popular location to |
| attempting to get every machine on a network to | | | | receive a UTC time source. However, an Internet time |
| synchronize to the same time. | | | | source is located through the network firewall and |
| The first problem many network administrators make | | | | security issues can arise from having to leave the |
| is the selection of the time source. UTC (Coordinated | | | | UDP port open to receive the time requests. |
| Universal Time) is a global timescale and is used | | | | Internet time sources can also be inaccurate and as |
| throughout the world as a basis for time | | | | NTP's own security system known as NTP |
| synchronization as it doesn't rely on time zones | | | | authentication cannot work across the Internet further |
| enabling the global community to base itself on one | | | | security issues can arise. |
| timescale. | | | | A far better solution for getting a source of UTC is to |
| UTC is also controlled by a constellation of atomic | | | | use either the Global Positioning System (GPS) or the |
| clocks which ensures its accuracy; however, it is | | | | long wave radio transmissions broadcast by several |
| regularly adjusted to ensure that it matches mean | | | | national physics laboratories such as NIST in the USA |
| solar time by the addition of leap seconds which are | | | | and the UK's NPL. |