Search Icon
MOBATIME Homepage Breadcrumb chevron icon News & MediaBreadcrumb chevron iconPublic NTP Server or local NTP Server – which is better and what needs to be considered?
Back to News
24.11.2023

Public NTP Server or local NTP Server – which is better and what needs to be considered?

Posted on
by
The choice between public and local time servers for your network is a significant decision based on a variety of factors.
Sideview from a NTP Time Server DTS 4135

At MOBATIME – Swiss Time Systems, we understand that the choice between public and local time servers for your network is a significant decision based on a variety of factors.

The definition of local and public NTP time servers

Local NTP servers available to a host
A local NTP server is often used to synchronize the respective host and its clients. This does not require high computing power or extensive RAM. In addition to an NTP server, other servers are therefore often operated on the same host.

Public NTP servers are available as an open resource
A public NTP server operated by various organizations or institutions and made available to the general public. Use when no internal or local NTP server is available or when an additional time reference is desired. However, public NTP servers may be subject to a higher load and are less accurate than dedicated internal NTP servers.

When considering a public NTP time server, you should ask yourself the following questions:

  • Network accessibility: Is your network configured for access to public time servers via the Internet? An unblocked UDP port 123 is essential for the use of public NTP servers.
  • Trustworthiness: Should you trust an external time source that can potentially be manipulated or do you prefer your own hardware secured by multiple source redundancy?
  • Alerting options: In-house time servers offer the ability to monitor and respond to reception failures through SNMP, email or other services.
  • Accuracy: As a rule, in-house time servers in the network offer greater precision as the packet run-times are more stable. Although the NTP protocol offers efficient filter mechanisms, your own time servers guarantee greater security.

Despite our recommendation to use dedicated NTP time servers for optimum network time synchronization, you will find a selection of currently available public time servers below:

By the way, we also have a public NTP time server for you, which can be accessed at “ntp-public.mobatime.com”.